Airtel — fake bill generated after permanently discontinuation of no. [protected]

Address: Kolkata, West Bengal, 700091

Website: www.airtel.in

I had a post paid airtel data connection # [protected] which had been permanently discontinued on 18th november, 2017 with the help of saltlake city centre-i airtel store & even i've paid the amount of rs. 70/- for the rental from 11th - 18th nov.17 as per airtel store executive. They have helped me to permanently discontinuation of the number. Few minutes later customer care called me & they did same. After few hours later the connection got the stopped permanently on the same day. Now i am getting a bill where an amount of rs. 1441.79 is showing as due which is totally fake & a lock in period amount of rs. 1200/- is showing in the bill. But as per my knowledge when i took connection the service provider representative informed me that there was no lock in period. So where is coming this option. You are requested to help me in this regards & waive off the fake amount.