CELL C Prepaid Line suspened for no reason, agents are not well trained to deal with queries

Again I am fighting with Cell C for the same query which was resolved just last week. Now I am told my expired contract which is now a prepaid account owes R114....whilst when I closed the account I paid everything that was due, because they wouldn't open the line if all that was due was not PAID FOR IN FULL. Today I am told I owe them and they have suspended my prepaid line. I do not owe Cell C anything on my previous contract, I only am in arrears for a router which is not in anyway connected to my prepaid account. Do we have to write to Hello Peter for matters to be resolved???????