Edgars refuses to pay refund

On 13 August I requested a refund on an accidental overpayment on my account. The amount is almost R3000. The response I got is that I need to send the documents again (which was attached to my original mail). I did as requested and was then asked to send proof of payment, which I did of course. I was then again asked to submit the original documents, which I did and was again asked for proof of payment. Today, I again submitted all documentation. This would be my 5th round. I even asked them why not just let me spend the money, to which they rep**** that my account was frozen because I was in arrears, which I obviously tried to rectify and then made the mistake of overpaying. They said I will have to open a new account - which I definitely do not want to do - but can't transfer the funds. I don't know what to do anymore... Edgars, if you don't have a measly R3000 to pay me back, just say so... This tennis match is driving me nuts!