MDB agents are the worst

I could like to lay a complain against MBD credit solution. I made a payment with them on the 16 of July using there payments link. I had to use my bank card number. On the 20th of July they took they very same amount. I have spoken to 4 different call agent none of them helped. I informed them it was a double payment I no longer owe them money, they are the once that owe me. It's been a month I haven't received any form of payment from them. I have proof of everything, on top of that they are telling me that they didn't take money from I have asked to be transferred to the finance department they refused.