stole my money

Last year mtn took money off my account for services that I didn request.. I logged several complaints nd they promised that they would refund my money.. Up to this day I have not seen that money... Last month I went instore to pay an account because they disconnected my services and I couldn't make any calls.. They then decided to deduct double the amount.. I phoned the call center nd the lady assured me that they would deduct it off the amount that they owed me.. Mtn is very quick to disconnect peoples phones but when it comes to returning money they take forever.. I try nd call they help center s but they are useless.. Mtn needs to get better service and get more competent IT people because it's clear that their systems suck...please pay back my money