Bad service

I did my online upgrade January, since Apple iphones wasn't in stores at all but sadly the phone i had, had issues and i took it back to the store nd they toldme to wait 7 days and they will send me a new phone, till today i haven't received any phone and im still being debited for something im not using, i tried to call MTN but they couldn't help me and some are rude and they hung up on you, i have all the recordings of how they mistreat you on the phone call, now its April 26 and still no help