MTN dont care about their loyal customers

This month it would be a year that I'm waiting for my refund from MTN. When I did my upgrade 2 years ago they upgraded my contract and never cancelled the previous one so I just kept paying for 2 bundles etc. They acnowledged their mistake and promised to refund me within 4 days, its been a year and after numerous e-mails back and forth they still havent done the refund. I did an upgrade over the phone in November, it is February and they ate still deducting my previous contracts debit order. I'm so frustrated! I feel its unfair that they ***** from us and we need to keep begging for them to rectify THEIR mistakes but when you return their debit order they list you on itc. I've been a loyal customer for 17 years now, I think its time to move to another service provider as they obviously don't care about me as their client. I spend alot with them each month and they dont care.