Airtel — service charges cut for pack never asked

I was unable to call for 15 days when i went to airtel office they told balance is zero, i was shocked as 15 days before balance was 300 and i did not use the phone
As i recharged on 7th may with 200 rs immediately 55 rs was cut saying masti pack is renewed which i have never asked before & airtel also didnot send any message that such pack has been started
After digesting my 355 rs it is informing
Previously most of the calls i used to do by airtel but after such a big cheat i switched over to vodapone i am thinking to stop it
Before this issue i was planning to start internet with this number but not now
If airtel thinks it will earn money this way its wrong thinking.