BSNL — Abnormal bill

Address:

Hyderabad, Andhra Pradesh

Sir/Madam, Last month i got 3G data usage bill 10, 700. I came to the BSNL office twice. Accounts officer showed usage of around 8000 on April 23rd, 24th 2015. I haven't used the 3G SIM all at that time. Can you please help in the validty of this abnormal bill. I have been using the 3D cell for data usage and the bill used to be around 150/- to 300/- for the past 3 years. Officer informed that i was notified message. But i was using the 3G broadband adapter, hence i didn't recieve any messages. My 3G cell number is [protected] and account number is[protected] Can u please help in resolving the issue. My mobile number where i can be contacted is [protected]. Thanks, Phani