Unfair blacklisting

Unfair blacklisting by Telkom Took a router with them,then canceled due to network issues.i called their customer care to settle my account,then agent sent me their banking details and reference number. I keep on receiving messages from their lawyers to say I didn't pay my account meanwhile I did,to find that their agent send me wrong details.now they have handed me over even tho I have payed,and send proof of payment several times...nxx I hate such service