OVER CHARGED FROM LAST YEAR

I previously was a Nashua Mobile customer and had no problems up until they closed! once my account was transferred to MTN I had been over charged. The first time I had reported it, MTN had given me so many reference numbers and every time I called there was some excuse or another. But last month the REAL DRAMA had BEGAN. I took a package of what should have been R299 per month over 24months and requested my limit to be at ZERO. The consultant had told me it would take 2-24hours (which had not happened) I went then to Coastlands and there I was given a ref number: *** for my data usage to be ZERO. last month I was billed R1111.10 and this month R1500 and some odd rand. I am not going to pay R2700 and some odd rand for a CELLPHONE BILL I AM NOT INSANE. this is Unacceptable! This is no fault of mine therefor I DO WANT TO BE DEBITED R2700 and some odd rand I cannot afford almost 3k out of my account. SICK AND TIRED OF MTN!!!