RIP OFF

I LODGED THIS COMPLAINT WITH MTN IN JANUARY. MY ACCOUNT WAS INITIALLY WITH NASHUA, WITHOUT FORMAL CUMMUNICATION, MY ACCOUNT WAS SWITCHED TO MTN. MY ARRANGEMENT WITH NASHUA, WAS A CAPPED AMOUNT ON BOTH MY LINES, NOT TO EXCEED R200 OVER AND ABOVE THE SUBSCRIPTION. I RECEIVE AN ACCOUNT END OF JANUARY, ONLY TO FIND OUT THE ONE LINE HAD A BILL OF R1700, i.e. SUBSCRIPTION R399, SO THE REST OF THE ACCOUNT, WAS EXTRA USAGE OF MB, THIS HOWEVER ISN'T MY PROBLEM IF NASHUA AND MTN DON'T COMMUNICATE, THAT THE ACCOUNT WITH NASHUA WAS SET WITH A CAPPED AMOUNT AND WHEN MTN TOOK OVER THE ACCOUNT, THEY DIDN'T TAKE OVER THE ACCOUNT WITH THE CAPPED AMOUNT. THE BILL NORMALLY COMES IN AT R780 MAX.... IT THEN CAME IN AT R2555 FOR JANUARY. FEBRUARY ACCOUNT CAME IN AT R1700, AFTER I HAD SPECIFICALLY CALLED TO CAP THE ACCOUNT. I REFUSE TO PAY THE BILL, FOR AN ERROR WHICH WAS DONE ON NASHUA/MTN SYSTEMS. NOT MY PROBLEM, YOUR INTERNAL PROBLEMS. I WANT MY ACCOUNT SETUP SORTED OUT BEFORE I PAY ANY BILL IN EXCESS OF WHAT WAS AGREED UPON. I AM STILL WAITING A RESPONSE FROM THE CALLS I LOGGED FOR MANAGER TO CALL ME, THIS IS NOW 2 MONTHS LATER