query - Airtel payments bank- opening charges or opening cashback

Airtel payments bank – on opening account,
a) how much you paid ?
b) how much credited into bank account ?

For me, they told 50 RS you pay and open account. 20 credits in next day, 30rs will credit in 3 days. But this 30rs didn’t credit to me.

The store person showed, either 0rs, or 50rs option on opening…. He said 50rs only works for opening.
Or
- every one got 20rs cashback?, for opening when 0rs option too. 

On speaking with customer care, they told on opening account, no charges, and Speak with store person and sort out. Stupid guys….