Trai — airtel postpaid mobile

Address:

Kolkata, West Bengal

I got my postpaid cug airtel mobile changed from postpaid to personal prepaid with 82 days rs 399 package in october.in november end suddenly the mobile sim stopped ; i added another package apprehending that earlier one was over. Even then the mobile did not function. I was hospitalised meanwhile and sent my brother to nearest airtel shop. They asked for the user to come in person. But i was bedridden. Yesterday i had gone ther after the doctor declared me fit. They said the not only the sim but the mobile number had been cancelled on 22nd dec, 18 and forced me to take a prepaid connection with same number.
I want clarifiaction as to how anumber could be cancelled when i should have almost 3 months prepaid charges in store and how can airtel force me to take expensive postpaid connection once again..