Need to be discuss here

Hi frnds, one of my friend given Rs.250 to a person in our local market, and given his sim of airtel, I don’t know what he done with that sim, now my friend is using Mobile office without any deduction from his account from past two months, and there is no restriction he can use it as normal mobile office user. He has only Rs.20 balance in his account.

I want to know is there any hacking about airtel, please discuss here if anybody knows, plz forgive me if it’s not aloud here, I just want to clear it, why its happening here as I m regular user of airtel’s mobile office from one year.

With thanks
Jatt