Telkom is the worst - its like signing a contract with the devil, there is no way out and apparently i am not the only one experiencing this

Telkom is the worst - its like signing a contract with the devil, there is no way of getting out of the contract: i cancelled a 3g contract with Telkom over 4 years ago in March 2015 and to date i am still battling to resolve the matter even though i went to the telkom service branch to cancell a number of times. I am now receiving smses (***) threatening black listing for the service i never used (there was no infrastrucure for wifi at the time ) The reference number is *** - the date of cancellation is 21 March 2015 and the CANCELLATION REFERENCE ***5 A. This was cancelled at the Telkom service branch at Woodlands Boulevard pretoria east. I am beyond furastrated and this is tarnishing my credit worthiness in the meantime.It is really unfair to list me for a service i never used, and cancelled over 4 years ago.