Deposit not credited, money not refunded

Casino: 20bet

Claim ammount: 5000 INR

I made a deposit on 4th December, 2021 of 5000inr. I was told the transaction was unsuccessful and that the money would be refunded. The money is yet to be refunded. I contacted my bank regarding the same transaction and they have confirmed that with the merchant that the transaction was indeed successful. On contacting the betting site, they just give a vague answer that they are "investigating my case", yet nothing has happened and no update is given. Today I got a mail saying that they simply wont mail back to me. This is outrageous