Airtel — complain about not getting proper internet speed

Address:

Vadodara, Gujarat, 390007

I have a portable hotspot of airtel with 4G data plan. At the time of buying they convince me for that I will get very good speed but now I haven't get proper speed I am getting speed of just 100 to 500 kbps and I try several time to complain but they respond very badly. And no action have been taken yet from the company side.