There is no solution which is 100% perfect to stop the spammers misusing the gambling chat.
There are certain solutions that can actually restrict spanners to a huge extent, but that would require setting intense restrictions which could possibly drive away legit gamblers thanks to the strict rules which is why casinos think twice before implementing these rules.
The easiest one to implement is that temporary ban the user who asking for money or spamming links after X no of times.
I have seen such rules in the trading exchanges platforms and it works perfectly to stop the spams.