I think you deserve to lose that money, you were already given the warning to make sure that the network is matching so there's no chance that your funds would get lost in the transaction but you still seem to have done the thing and go for it anyway which is stupid in my opinion, I had that habit of heeding the warning when I'm transferring funds for awhile now and it would be a really good thing if you also learn about it too because most of the time, it saves you the headache and as @tabas have mentioned, there's bound to be another problem coming your way if you really want to solve this problem that you've got.

Exactly, Coinbase might just ignore him because they have already given him warning that he wants to use the wrong network. Since they stated it that sending coins to the wrong network means that you will lose your coins, will give them the boldness to seize your coins. However, some exchange will not accept your transaction when you want to use the wrong network. OP, should see what he can do to get back his bitcoin but has 50/50 chance.

Well, your information is very limited, and with what you have provided, it will be very difficult to ascertain the real root of the issue and why you didn't get your bitcoin on your coinbase wallet.
It's important you know that sending and receiveing bitcoin is very easy, and the network doesnt operate like EVM network where different blockchain networks makes use of the same wallet address, thereby making the chances of send funds to the right address but over the wrong network really high.

You should really find out from the casino which network you sent your bitcoin over, and check your coinbase wallet to know which network you copied your receiveing address you pasted on the casino from, if both match, then contact the casino's customer care and let them know that you didn't recieve the funds the claim they sent, they should provide you with the ID of the transaction to prove that the funds was really sent to the right address.

My first time hearing that an exchange is against gambling? Why and what are there reasons if I may ask. Are they government?
How did you know about? Is it written in their ToS or it is out of your personal experience with them.

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I wish the Op can read this so that they will not lose their fund. If OP contacts Coinbase support and is able to prove they sent a coin, it will definitely be rectified. Who knows if OP sent the coin to a wrong/phishing address.

Many crypto exchanges can confiscate funds if it is coming directly from a casino gambling platform, their excuse as usual is money laundering, they also use the same excuse to confiscate funds coming from a mixer or CoinJoin transaction. If you want to convert funds in your casino account to fiat, you have to first of all deposit it into your self custodial wallet and from there to an exchange.

Usually on some leading exchanges there is a warning before you make a transaction where you are asked to double check before making a transaction whether the address is supported or not. Moreover, there is no screenshot that can be shown so that people can judge whether it is your fault or the exchange's fault. But in most cases the mistake is more often made by the user because they don't check first before making a transaction.

It could be as you said that you are not using the correct network because you mentioned there were no other network options so your transfer was not successful. The solution is to send feedback to the support team and ask them to double check the transaction you made if it was their fault.

The warning given to you is the normal warning that ost platforms and exchanges do give so that you can confirm your address and the network you sending to, if the two networks are not march, then you can lose your funds.

Now this information is not complete as we cannot be able to verify if there transaction is broadcasted to help you check if it has dropped or it was delayed due to either low transaction being used; and you didn't mention how long the transaction has been sent out from your casino wallet.