sudden excessive ADSL usage

From using no more than 1GB per month data on Telkom internet suddenly I am being told I have used almost the whole of the 10GB in 12 days. I have contacted Telkom Internet Abuse and checked my computers for virus etc as suggested. I have also installed a usage tracker on my home network which is showing only 2 GB usage in past month.<br> I contacted SAIX as there online usage stats show this unbelievably high usage but they said I had to contact Telkom Abuse which I tried to explain I had done so 3 times and still got no further.<br> How can Telkom prove I have used this much data ? I do not download movies or music or play games merely brows/ use email etc.<br> Something is not right.