MTN-absolute *******

I was a little late on my contract payment but paid R300 into the MTN account but yet they still double debited me R569.00, I then went into a mtn store at the glen shopping centre and explained my problem the lady that helped me explained that I had a choice for them to debit the money back into my account and it would take a week, this was 2 weeks ago and I am still waiting for feed back, I have tried contacting head office but they ignore all of my queries ,this is absolutely ridiculous... how can they call themselves a service provider with such horrible service. Its easy for them to take money from you but as soon as they need to dish out the money you don't have a chance