data usage!

I have two accounts with Telkom. 1 being my cellphone which is on an unlimited package and the other being my wireless router which is on the 7.5gb daytime data and 7.5gb nighttime data. our 7.5gb for this month depleted by the 9 October-which in itself is strange as it usually lasts until the last week of the month. last week we purchased an additional 1gb which depleted in a day, we then purchased an additional 2gb which depleted in 2days. we were not even home for most of this time so this is absolutely unlikely that it could go so fast. we called the call centre this evening and spoke to someone by the name of Mandy-she was absolutely useless and kept us on hold for 20mins before providing no solution. she then put us through to her manager Jabu who told us that they cannot help us. I NEED A ANSWER ASAP as to where my data went!! this is unacceptable that it would deplete so fast when we don't even download anything. I need a detailed print out frm Telkom showing me what ive used, when and what time and if this cannot be provided I need a reimbur*****t as this is costing me way to much money for no reason!!