UNABLE TO CONNECT TO NETWORK IN USA.

I am a postpaid customer for airtel. I traveled to the USA on March 31 2019. Prior to that I bought a roaming pack for a whopping Rs 3999/- from Airtel. However, once I reached the USA I found that my AIRTEL SIM could not connect to any network. Therefore unable to make and receive calls and SMS. The Roaming Pack therefore is impotent and useless. Have written to Airtel asking for refund of roaming pack. There is no way to contact them from USA unless you are ready to pay for an international call. SUCKS BIG TIME!