Wesbank makes a mistake and refuses to acknowledge their own documents

In August last year my car was written off, my insurance settled the debt and Wesbank refunded me for the tracker. Four months later in December I am contacted by Wesbank saying that they made a mistake and they shouldn't have refunded me and they would like me to return the money. I let them know that I do not just have that money laying around as it's 4 months later. I asked them to reload the cost of the tracker for the period remaining and I will pay it off. Expecting it to be on debit order I thought nothing of it until I received a phone call at the end of January that my payment is late. I was informed it is not on debit order and I said it's okay I will pay it monthly. Now at the end of March they are seeking the full amount and sending the amount to collections. I've emailed collections and they don't seem to be reading the email stating that my monthly repayments is ~R127, they keep repeating the same email and it seems like there is no human on the other side.

This by far has been the worst experience I have ever had with Wesbank.