Airtel — bill follow up calls - for incorrect broadband connection

Address:

ADITYA A203, COSMOS HERITAGE, NEAR TIKUJINIWADI

Hello
I am facing a lot of frustration. Got at least 50 follow up calls for bill payment against incorrect Broadband connection.
There was offer for new Airtel connection - fiberoptic during May'20 at our complex. I already had copper connection and wanted to upgrade.
My details were taken by the team and then I was told that since it is upgrade I need to reach nearest Airtel gallery.
I reach Airtel Gallery at Hiranandani Mildows in Thane during 1st week of August'20. I was told that upgrade will be done.
While this upgrade was done the team connected fiber optic and taken away my copper modem. The broadband number connected by this team was new which I realized the after 15 days of connection. I had a lot of follow up and with the help of Nodal officer Airtel got my old number reconnected and upgraded. I had paid all dues against my old number which is used by me for more than 10 years now.
I had reached Customer care. Send formal complaint mail to Nodal officer Airtel, Mumbai but still I am getting calls for Bill payment.
Request concrete action against all such calls received.