The letter that support sent you does not say anything about you being banned. Rather, it looks like they cannot identify you correctly.
Have you completed all the steps that you were asked to do?
What browser are you using? Was there an update? Likewise, are your cookies and your connection OK?
The casino might think that you will have matches in your history with another account, and perhaps the casino suspects you of having multiple accounts.
I just don't understand why they can't send me an email or notification to make the thing clear, I just wasted almost 1 hour with panic to figured it out what happened until I decide to withdraw some funds.
Do you think you're the only one with questions that a casino should answer immediately?
Read all the topics in this section.

I did all the steps, nothing works to me. Waiting for the response now.
I think you don't get my point. I have never blamed them for responding too slowly or required them to reply me immediately

The problem here is I can't play, can't withdraw, and no message from Bitcasino.io.
If there was an error with the website, they should make an announcement to inform everyone.
If there is an issue with my account, they should send me an email to notify me.
Up until now, I still can't be sure where the problem is. Based on what I've seen from other posts, it's highly likely that the issue is with my account, because if it were a website problem, they should have posted an announcement after few hours.