Airtel — no service on sim

Address: East Godavari, Andhra Pradesh, 533001

I hold airtel phone number [protected] and am
Not having service since 6 days! Had visited airtel office and they had put my sim on other phone and tried making it work but it didn't! Then their superior on further inspection said that this is some h2 series sim and those are having trouble now!! He assured me that i would get my signal back in 24 hours but i didn't!! Kindly suggest what to do coz i'm a chartered accountant and this is the busiest time of the year and i have only one number!!