Anonymous on "airtel postpaid bill complaint"

hi this is anil kumar
m no : 9550282712
Relationship Number 1145129443
Bill Number 739403284
bill plan: 300 per monthly
bill period 17-Jan-2015 to 16-Feb-2015
I want to register a complaint against airtel that i got large amount of bill Rs 783.78 the amount is large bcz of Usage of Internet, and i have 500 mb every month in the bill period, i have just used only 480 mb
but in the bill they showing above 500 mb data used, every month they giving hidden charges on data or calls. i got a msg when after data is crossed 420 mb and i reduced surfing of inter net and i calculating every time then how i crossed my allocated mb.
Looking for a justice and reply.
thanking you