Account problems with Edgars

I have the following problem with Edgars. I paid up my Edgars account on 2 May 2020, as I knew that Edgars was going through unbundling or debt rescue and I didn't need or want any debt collectors pursuing me. Over the last two months I have received 4 sms messages saying that I owe them money (now R305.85) and the amounts keeps getting more and as at today I am told now two months in arrear. This absolutely infuriates me, as I have a very clear credit record. I have now been to Edgars Eastgate (they were under going a system change and could not assist me, then to the George Edgars on 29/9/2020 and they could not even find my account number on the system. I then called a number they gave me on 30/09/2020 and spoke to a Benne**** and he said that he could see that I had cleared my account on 2 May and that there were no further purchases after that, but he could not tell what the balance was for, to which I said I will not pay this balance, as I do not know what it is. He made a note regarding this. Today (9 October 2020) I once again received an sms stating that I owe this R305.85 and to call ***, which I did and spoke to Umesh. Same problem, they cannot see details of what makes up this amount. He then gave the Head Office number ***, which I called and the machine said they are unable to assist and can I please visit an Edgars store where they will assist me. What am I to do? Can someone please advise what is going on and what can I do legally, to get this sorted out. I am not simply going to pay this amount of mount, as I did not purchases anything. Thank you, Kind regards. Barry