Telkom not cancelling account after numerous requests

I have cancelled my Telkom account twice. Every other month, I get a new invoice. What do we have to do to get proper service from service providers?

Once at Vaal Mall, the consultant did not attach the cancellation docs on their system, and once at Nortgate Shopping Centre. Where the consultant told us that the cancellation docs where not uploaded by the consultant in Vaal Mall. The consultant at Northgate assured us this was taken care of now.

So 3 months on, I see a deduction from and invoice from Telkom.

Can anyone tell me why?