Airtel prepaid service - Very slow internet almost unusable even after complaint

Even after opting for *g connection (with supposedly high connection rate) the speed offered is pathetically slow! With this slow speed i feel cheated. I cant use daily data effectively. I had even complained earlier to airtel using *** but to no avail. During rain and cloud during evenings or before ** pm, this problem aggravates.
For example i was trying to make payment to dish tv-the connection simply hanged .money got debited but not registered due to the network speed(got frozen during payment) I had to redo using the bsnl wifi connection( that i had installed to overcome this type of issues.

I ask why we are charged so heavy- when they can't provide decent service.
Even after having complained. To airtel operator
With clear connection problem not only by me but my wife, and daughter -I even provided their phone nos connection to the very same provider ' airtel.'
After all this i had to opt for broadband connection of BSNL (EXTRA MONEY) Even with all the daily data going waste ( cant reverse it since we haved in advance myself ** days *GB plan packge and my wifes advance for yearly prepaid service from airtel