Airtel — bill or receipt for sim card

Address:	Raigad, Maharashtra, 410203
Website:	www.airtel.in

I have purchases an airtel sim from airtel gallery, location khopoli.
The airtel store representative told to pay rs. 50/- for sim. I paid rs. 50/- and after 30 mins. I got a call from airtel store representative (The senior representative) from same location that i have to pay more rs 100/- for sim, or else it will be blocked. So i asked for bill receipt/invoice for sim purchase. So the person replied there is no bill receipt/invoice for sim.
This is to be solve to stop the corruption.