[Resolved]  Prepaid SIM Card — booster pack

i am using airtel prepaid simcard for last 3 years. i recharged with rs 100 and booster pack rs 123 on easy recharge. today 18-12-09 i received a message from sender (airtel) which says my account credieted with bonous talk time of rs 10 for recharge offer. after that my simcard takes rs 1 for each call. i need explaination why its happening. my mobile number - [protected].