Randridge branch

Ive upgraded my mobile contract in September. Was told by the Randridge mall branch manager Tyrone that I will not pay any additional charges except a very small prorata amount. I have received my account Oct and it was over 1000.00 more. November invoice is even more than that. When I inquired this from the accounts department I was told I did an early upgrade and therefore payment for 2 phones. I explained the situation but nobody assist me. Went back to the branch and was again informed by the same manager that its billing department that messed up and he will sort it out. After 5 days of waiting for a call, I phoned the branch and was informed the manager resigned and did not return back. Now my debit order went off yet again with the wrong amount. This is the worst service I ever received in over 20 years with MTN. I guess my only solution is to go open a case at the police for theft!!!!