Multichoice very inconvenient and inconsiderate

My mother recently payed for our DSTV subscription which is in my name at a dstv self service machine at Maponya mall, our subscription is R495 including the explorer subscription, instead of punching in R550 she punched in R5500, she later on noticed when she got home that she had made the mistake, upon payment of the amount the self service machine did not generate a receipt and gave the error message that it was out of paper, we contacted the contact centre to report the payment mistake that happened, we were asked to provide a bank statement, both my ID and my mothers ID, we scanned the documents to a contact centre consultant and no resolution for the refund, we sent the documents again we received no response and no resolution. We then took it upon ourselves to go to the walk in centre for assistance, little did we know we would come back without a resolution for the refund, instead we were told we must provide proof of payment, what is crazy is we provided the bank statements to prove the funds left the acc and our subscription acc has a credit with the amount in question, why should we be unconvinced by idiotic business processes when we have provided all that they had asked for, where should we now get a proof of payment since the self service machine ran out of paper to print the payment receipt