If you want your fund immediately then close that account and transfer your fund, you won't be able to open the same account in this bank in future.
You need to make several follow-up, try to talk with Manager, and convince him saying, I was fallen into betting and able to make money and hence got credited into my account. I won't do this again, I wasn't aware about this so much. Show him details from that betting site or app, to match your trxn. Hope, it will get resolved.
Other alternatives 1, transfer your home branch and make sure they will do it, most probably will do
Other alternative 2, connect with Nodal officer or Principal Nodal Officer, branch employee, may further create problems if their ego will get hurt.