Airtel — unethical behaviour - i recharge 1 year subscription but got validity for 360 days instead of 365

Website:

airtel.in

Today i recharged for 1 year subscription of rs.5801 (Infinity hd pack) with airtel digital tv. But the validity was showing until nov 19, 2018 instead of nov24, 2018.
When i contacted customerservice i was transferred to 2 different people and landed with the floor supervisor, i was told that validity will be only for 360 days and not 365 days. When i asked him to take up a complaint on my name for this issue, he refused saying its not a complaint and he wont take it.

1. Why does airtel cheat the customers by saying 1 year subscription and reducing 5 days in it? Where in the world do we have 360 days for 1 year?
2. How can the customer service agent refuse to take up a customer's complaint?

I would like my 1 year subscription to be given for 365 days.