MTN overcharge

If i could give a tenth of a start i would because a whole star is too much for them. On the first of Mrach a debit order went off my bank account for R1800 instead R478. I have been calling since and everytime they tell me we are logging the query with finance and nothing has happened. i receive sms saying query has been closed, and yet again when i call, no one can tell me anything, whether i will be getting my refund or when that will happen as MTN took more than they should have from my bank account. As a result of MTN taking almost 4 times what thy should have taken, i missed one debit order for my son's fees as i did not have sufficient funds in the account. I incurred R61 fees for a bounced debit order (fees for standard bank prestige account) and my son's fees is still owing. I have not been able to get any help whatsoever, regarding getting refunded my money so i can pay fees and have money for upkeep. but all the consultants i talk to do acknowledge that my account show an overpayment.