Inefficient accounting at Edgars

I have previously vented my complete dissatisfaction with Edgars. The situation is now almost ridiculous. They insist that I owe them money which I do not. I have e-mailed them with details of payment, my bank has sent them proof of payments, their staff member at Eastgate, Winile, has proof of the three payments and not only that, but my husband and I personally visited Gabriel at MBD (their collection agency) and showed and sent him proof of payments. The first payment of R600 went through but strangely the next two payments seem to have mysteriously not gone through. MBD staff phone me constantly at around 0730 in the morning and then just disconnect. And I constantly get SMSs saying that I owe Edgars money. This has been going on for around 8 months and I am sick of it.