Airtel — amazon prime membership on airtel recharge

Address:

Chennai, Tamil Nadu, 600010

I am posting this complaint hoping to get a resolution. I have made a recharge of 349/- for the month of march. Airtel offered a 28 day free membership for amazon prime but i couldn't get it activated. Called customer care twice but no use. Everything is fine except this. When called the customer service 2nd time, they said that the support tickets has been closed on the same day it was raised. Please help me resolving this issue as i am losing the validity of prime membership.