Airtel — Cheating in the name of offer

Hi,

I have been using airtel broad band connection for more than 10 years now, recently, i had an offer while upgrading my broadband plan, the offer said 1500 for xtreme box and while booking for xtremebox, i had an option to choose 1699 rupees for a year for OTT content(hotstar vip and zee5). The box was installed on 13th November and i paid 3199 in cash 1500 for box and 1699 for OTT content as mentioned in the app while choosing.

After the box was installed, I paid the total amount to the person who came to set up the connection and when the box got activated, i was not able to access any subscription, when i called and asked i was informed there was no such offer in booking and all money has been taken for installation and activation.
I registered a complain and every day they keep dragging by asking the same information as though that's the first time i register a complain and extending it 24 hours and after 4 days, when the call goes to supervisor he tells that the connection was only for a new customer and not for existing customer, when i called to broadband department, they say they are not aware of such offers and only new customers get that offer. When i asked why would the app show the offer to an plan upgrade since only existing customers can upgrade a plan, the person went silent and there was no reply and all i understood was that I am never getting the offer it was just to lure existing customers to spend money and airtel cheats them. I am attaching screenshots from the app to show that the offer was provided on plan upgrade

[protected] is my digital TV id