Trai — transfer of my contact number without my permission

Address:

380055

I am using a prepaid number of airtel since last 8 years. On 15th november 2017 at 5pm my mobile number went out of service. I rushed to airtel store and asked about my number not working, the airtel employee said the number which i am using has been transferred to another person.

By requesting a lot i got the know that the person has given in written that he is my friend and i have no objection if he transfer my sim card on his name. On the other hand i am totally unaware about this situation and who that person was. Now i am traing to get back my sim number but since 16th november airtel has given me a sim card whose service is not started yet.

Kindly help me in getting my number back and take strict action against such liberal activity happened.