[Resolved]  Bought A Postpaid Airtel SIM Card — after one month my sim become invalid sim

sir,
I bought new airtel post paid sim after submittinting all required documents. It went all normal but after a month, one fine day when I recharged second time after two call it stoped working. When I went to airtel show room they say my sim will not be activated again as it may have negative varification, but I confirm you that no one did the verification telephonically or personally at my house or office address.
How can such a reputed compay do this to any customer. I have used airtel earlier when I was in New Delhi and Dibrugarh also my brother is using it for eight years now. please help in getting my sim activated. My sim no is [protected].
thanks.