I can't guarantee that this would help but try posting this on AskGamblers or Casino.guru they might be able to get more answers from them, they've been known to help gamblers that have issues with gambling sites.

they have an ANN thread here but it looks like it has been abandoned, their representative also has not been active for 5 months.

Why the support claiming that you don’t have funds on your wallet?
I’m curious about this since you’re about to withdraw as per your statement.
The site should inform you about your violation, its not fair to left you hanging around. The only way to escalate this issue is to post this on Askgambler or other platform that might help you. I’m not sure how this site works but if their support is like this, I think I should avoid this site.

The representative of this casino was last active in December last year, so he hasn't maintained the announcement thread for a long time, you can move this thread to scam acusation as the member suggested above, but I doubt you will get a response from the coinzion representative so the problem you are facing can be resolved, but at least your post can increase awareness to avoid playing at the casino because people who don't know about it can experience the same thing as you experienced, but it would be better to answer or include a more complete screenshot so that doubts about the issues you are facing can be clearer so that it is true that you are being scammed Not the opposite.

If truly this has everything to do with OP breaking the terms and conditions rules then they should go into details, how will they seize that high amount, and all they can say is he breaks the terms and condition, so good bye to your money? Is that how things should work? OP I blame you and not the online casino, why are you using coinzino? I've no relation with this online casino and I am positive that many people don't have know this online casino as well.

New online casinos can steal money from you if your money is attractive enough to them, they can easily change the terms and condition to their own taste just to rob anyone, this is the problem I have with online casino and their terms and conditions that never stays in one place for long. Are they doing this knowing that it's the only way they can rob people and no law can make them pay what they owe? OP like I said you are at fault.

Stay away from online casinos that are not commonly used by gamblers on this forum, you are inviting trouble if you go out there and look for any online casino yourself, scammers can create online casino hoping to use the terms and conditions to steal from people and they will run the business for a long time because terms and conditions is terms and conditions.

If there's a proof from OP about the balance of his account, then this can be a strong case against the site.
Wondering why the site are not disclosing the reason for being blocked aside from their general reason which is "You violate the ToS".
Is this a normal practice for every site? Well, what you can expect from a small gambling site like this, for sure there are some irregularities here both with the site and the OP.

From the images provided above all I can say is that; both the Op and the support team were just beatin ground the bush. It was clear that they won't investigate or open your account due to the fact that you only got the same response with different wordings, read your chat with with the support and see what transpired between you two. And since the casino has refused to tell you the rule you broke it is now clear that they are only looking for an excuse nothing more.

Btw, did you by any chance take a screenshot of your account balance because the casino is currently claiming that you don't hae any balance and how do we confirn that your claim of having an account with ~$3,000 closed is true?

Just as others have suggested open a new thread in scam accusation board create a flag although the representative here on bitcointalk is no longer  active, so that those who find your post convincing can support it, and your thread in scam accusation board might also help others become aware of the shady business of the casino.

OP at first your evidence is quite ok to have provided the chat but not complete. You did not put up your transaction hash here so it would be verified to know if truly you made such deposit into your casino wallet yet.

Secondly, the casino from the beginning of the conversation especially the customer care you contacted has no clues of your offense meaning he or she is not I the know of what really happened and has refused to make further inquiries and it is likely they have refused giving out the information to the customer care so as to communicate you properly.

I checked their announcement thread and discovered that for quite a long that their account has not been active here and it was created October last year which means it is likely not a new casino.

Lastly, did you use VPN to login other while you were playing and winning heavily with the casino and after a while you decided to not login without VPN?
These are the little things that gets such a penalty from the team against their customers.

Afaik, He didn't deposit 3000$ but rather his account contains 3000$ now after his 3rd time deposit and win. Probably he deposit less amount than that and just manage to turn it to 3000$ when he make the withdrawal. He mention that he keeps withdrawing until that 3rd time which means he is on winning streak that triggers casino investigation.

I’m not siding with casino here but most of the cases like this that newbie magically turn small amount to 3 grand or more always involves cheating on the casino games. The casino is relative new which is always being target by abusers since they knew it has a weak reputation.

Security team is the one handling the account investigation while the support just forward information to the customer. It's normal that live support is not aware on his issue initially.

That's the main problem. If you say I am guilty, what is my offense? OP has argued that he didn't violate any of their terms and condition, so the crime or scam section of the casino should explain to OP what is the crime he committed and OP should be willing to bear the consequence of the ToS being violated. This is one of the dangers of playing games in casinos that are small, new, or have no reputation in the forum. $3000 is not a small fund but I don't think the casino will want to kill its reputation because of this fund. I will encourage OP to still contact them and keep explaining the issues to the support team. If they think it has been moved to the scam section, OP should at least get information from them about the status of his account.