Well what ever we explain to u, would be useless unless and and untill u ask this exact question to
AOTR your area of BSNL !!!!
One thing I can tell u are in side free limit... in did 1 GB = 1024 MB so, 2.5GB means 2560 MB and u are in side the limit...
So ask this same question in
writing to
AOTR mention ur EMail and try and give a FAX number to, ask for explanation within 48 hours as mention ur billing due date is near !!