Airtel — sim swap grievance

It's been 2 weeks i've been running from one airtel store to another to get my sim swap in this pandemic, and after all the procedures my sim does not get registered to the network and the retail store always say "sir please buy another sim and try again" i e totally bought 3 sim cards and this problem does not go away, they say everything is right but from back end issue is there now someone tell me what the hell am i supposed to do when it's not even my fault who is disabling my sim.

Ph no of sim swap: [protected]

Call me if your the representative of backend who is responsible for sim swap : [protected]