Bad pro service!!

We visited the place as a group early April 2025. Paid a deposit for brokage fee and upon requesting a refund(after they confirmed nothing was broker), they realized they paid it to the wrong person (emails seem to have been hacked). I tried explaining and sending proof that this was not me and the other email address is clear a Gmail account. I was told there is nothing they can do, I need to open a case. How do I even open a case on a transaction i was neither a sender or receiver? Worst experience ever!! we never got the deposit back.