Billed for data transactions and no details!

I received my billing statement in November which stated that I had used in excess of R3500 in data transactions over a 3 day period - bulk which happened \overnight"<br> I called in immediately as this is impossible - South Africa does not have the internet capacity to allow you to download a terrabyte in such a short period - never mind off your cellphone!!! <br> I have WIFI automatically connected at home and therefore never use my data bundle unless I am out on the road.<br> I have asked numerous times and received a long list of reference numbers to get clarity on exactly what and when these downloads took place. I have only received a list of gibberish that means nothing to me.<br> I want clarity on exactly what MTN is billing me for. <br> MTN cannot just bill me anything and not give me proof of purchase.<br> <br> This complaint has been running for over 3 months. I am now in credit for almost R5000 as I reversed the payments to get an answer - but had to make payment before my line was cut."""