rain paid up letter

Worst experience ever I received a call for collection for a Rain subscription, the guy who assisted me did not explain all the other charges and interests but only the principal amount due. After the agreed payments, I did not receive any settlement letter, instead, I was told there was still an outstanding balance in interest and charges of R150 which paid on the 30 April. I now get surprising charges for invoices I did not subscribe to of R355.06. I made payments on the account to settle it., I have been trying to get a paid-up letter. But when I call, I would hold for over 30 minutes only to be dismissed like my matter is not that serious. A consultant will tell me the matter will be escalated and that happened twice already , please find a way of sorting out this matter asap. Ref No: RN***