Airtel dongle

Hi All,
I have purchased postpaid Airtel dongle.
Time of selling the dongle they told me that you will be getting 5GB monthly and amount of dongle 799 INR will be waved off from your first bill so the would be free.
BUt when I received the Dongle I got only 4GB, after that I received the first bill amount of 1032 INR.When I asked to wave off the 799 INR no one ready to entertain, only call bouncing.I complaint I told by one your seller that I will going to get the 5GB, they said there are no such plans?
They stopped my dongle and said that first pay your bill and your dongle service will resume.

I paid amount of 1032 INR to one of Airtel guy who came to my office to receive the payment.I have the bill with me.
And next month again they sent the bill and amount is 1750INR saying that one extra month rental is added,however my dongle was not in service.
My airtel dongle number is 7738150736.
After that they are calling me from different numbers and threatened me saying that they are calling from Delhi court and will file a case against me.

I am still ready to pay the one month amount even though I have not used it more then 5-6 days.
I don’t know why they commit and why don’t they fulfill it.
can any one help please.
I am really disappoint.

Still I did not received any call from Airtel.
YEs I am receiving calls from people who are threatening me to pay the bill. People calling me from different numbers ,and saying that they are calling me from Delhi court and bla-bla.
Could you please look into this matter ASAP.

Thanks in advance.

Receiving threatning call from –8107718094
Mr.sub Ins Rajendra singh sekhwat–Delhi

Thanks
LM