Biggest mistake ever...

I feel harassed by Cartrack , I had made a payment on the 14th of May for a missed payment of April , after making the payment I sent proof of payment to cartrack whatsapp contact number ,the payment was acknowledged. On the 15th two debit orders went off and I asked them to refund one, they kept giving me run around telling me the payment was not allocated. I asked them to allocate it and give me a turn around time ,they said 72 hours...after 72 hours they said no turn around time and the person started being rude, I went ahead and reversed one debit order and tell them to allocate the payment I made via EFT as I used a link from them , even today the payment has not been allocated...I am receiving calls, emails ,sales, whatsapp conversations and I still keep telling them the same thing... I do not know what to do anymore cause I honestly feel defeated