Frustrated Vodacom customer

I am very frustrated with Vodacom. I stopped my contract over a year ago and went over to prepaid. When I did this I paid my account in full in store. However more than a year later we app**** for a loan at the bank and it wasn't approved as I have an account in arrears at Vodacom which I knew nothing about. I didn't receive any calls or received messages to notify me that there is an amount outstanding. Now I have this against my name. And the worse is when I phoned Vodacom to find out regarding this it was only R58, which I would have paid immediately if I knew. Which frustrates me even more it trying to clear my name with Vodacom. I have been to the store twice for help which I didn't receive. I also called accounts after I have paid the outstanding amount to get a settlement letter. They said I would receive in 48 hours (which was suppose to be on Thursday the 28th). I haven't received anything yet.