Airtel — Mail ID updation

Airtel T. Nagar North usman road chennai outlet forced me to recharge Rs. 219/- as first time recharge when I converted post paid to prepaid on[protected]. Moreover customers are forced to download airtel app to get outgoing call activation for prepaid connection. You can not force customer to use airtel app and it should be optional. Is it mandatory as per airtel rules. If so look into it and re consider the issue. Airtel is denying customer to update their email id through their app to avoid registering grievance or complaints from customers. I have updated my mail id through airtel app from T.Nagar airtel outlet and my mail id is also verified from the app. Now more than 6 days past it is still not activated. mails sent to [protected]@in.airtel.com are retured back with automated message maid is not registered. contact 121 to update your mail id. But the customer care no.121 does not have the option to register mail id which the airtel is not aware ?. please wake up and resolve the issue immediately.