Billing and Accounts

I'm very angry at Telkom and the way they do business. I personally went to telkom store to ask how much I owe and paid the balance in which no invoice was sent to me and no phone call. Now yesterday I get a phone call saying I owe R600 more cause my account was handed over. I was not told when I went onsite to request the balance I owe. All because I cancelled my services now I owe telkom. That's ***** according to me. We rather take the matter to court cause I paid what telkom said I owe. No extra costs. Please fix your mistakes.