dissapearing internet data Bundles

i was billed 1.4Gig for browsing a few pages,considering the time i spent on them and those being the normal daily transactions and also that i normally use 2Gig the whole month. I called the call center for help and they just told me that they couldn't help me because their billing system was correct. i asked help from the supervisor and she also told me the same story and offered no refund or solution all she said to me was that there's no way forward. The worst part is that if i want real help i must pay for itemised billing in order to check what i already know. so dissapointed as a long term, loyal paying customer. all i was asking for was my 1.4 Gig and for them to correct their billing system. thanx