vodacom billing

i have been a vodacom client for many years until recently. i received my bill in September with the bill of R5100, it was unpaid due to the bill higher than my normal salary. When doing enquiries i was told i have used more than my data bundles. The following month my bill was R8000, at that time i was not touching my data at all.i made arrangement even though i was not happy with the bill as some of the data was used while i was at work and some while i was at school with my wifi off . Some usage showed that i was using at night meanwhile at night im using my varsity data. That was not making any sence to me as to why and who would have acces to my wi-fi.i however made arrangement in the month of November and i was told that my debt id aound R14000. i did ask if no other cost i will incur after arrangement and it was confirmed that is correct. Surprisingly todate im told i am owing R18000 and yet my lines were suspended completely after the arrangement that was made.my number ***