Airtel
Net work coverage problem

I have been using airtel simcard 97o1889870 post paid for the last two years. but off late it is not functioning. I have even approached the head office at begam pet hyderabad. but of no use. iam in fix as to what to do.my repeated calls to air customer care haven, t helped me. iam suffering a huge loss because of the non-functioning of my simcard.hoping that you would attend to my problem and solve it soon