TELKOM REFUSES TO CANCEL MY ACCOUNT AND CONTINUES TO INVOICE ME

I have been trying to cancel my telkom account for the past three months now, I've been unsuccessful and i keep getting invoiced for a service i don't use , I HAVE TRIED CALLING,GOING IN STORE AND VOICING MY FRUSTRATIONS ON TWITTTER. TELKOM IS THE WORST SERVICE PROVIDER I HAVE EVER JOINED.