overcharged by 32 thousand rand

I have a small medium business account with MTN. I have a a monthly data limit as per contract, so when I run out of data, I ru n out of data. I can then choose to buy a bundle. My monthly bill is around R1000. Then, suddenly, in February they charged me. R14000. And March R12000. It is on debit order so when I found out the amounts had already gone off and the next bill was already on R10k. I reversed the payments. MTN has suspended my services. My clients can not reach me. I have phoned call center 4 times (holding on for hours each time) and escalated the matter. I did not authorise for the limit to dissapear. Nobody is getting back to me. Call center is now again not available, closed down. I am a single mom and do not have R32k extra spare. It is a mistake on their side. It is damaging my business.