FNB and MTN ganging up on their own customers

I went to MTN to cancel my home internet somewhere in July, I am still being debited , I made a cancelation at MTN store, when I go to the store they give me MTN 083135 number, when I call the number they tell me to go to MTN Store, sad part they made sure that their debit orders cannot be stopped/cancelled/reversed , when I call FNB they say there is nothing they can