Airtel — 4G hotspot- cheating customers - don't buy

Address:

600096

I bought Airtel 4G hotspot 6 months advance rental plan in airtel store located in S P infocity, perungudi, chennai and I have paid 3900 RS at the time of purchase. And after one month I have paid tax amount Rs.585 . Now they generated bill RS 4800 and ask me to pay and they disconnected the hotspot connection. I have contacted the Airtel store located in SP info city, perungudi and Airtel customer centers but no action. Still I am struggling.. Please don't buy Airtel 4 g hotspot and it's a cheating business.
Airtel hotspot no: [protected]..