Trai — airtel giving same number to 2 people

Address:	Gautam Buddh Nagar, Uttar Pradesh, 201304
Website:	www.airtel.in

I took a new connection from airtel bearing phone number [protected]. After successful verification the phone was activated on 12th sept 2017. I shared my new number with my friends, relatives and collegues and after some time people started calling me on my alternate number saying that i gave them a wrong number and that number belongs to someone else. When i called the number it was infact picked by another person who said he is the owner of that number and has been using it for the past 3 years on the vodafone network. I validated the number digit by digit and it was exactly the same number. I have been calling and emailing airtel support and all they keep saying is "this is not possible" i am really getting frustrated and airtel doesnt seem to acknowledge the fact that it allotted me a number that was being used by someone else.
This is a grave integrity issue and airtel is being very careless and strict action should be taken againt them for such a careless thing.
Regards
Faisal