Airtel / 3G Dongle — 3g Dongle not working but they said active

Address:

Chennai, Tamil Nadu

My 3g airtel dongle number is [protected].
I had been purchased this Feb2013 and worked for 1 month with full signal in my Desktop.
Now on Mar2013 after first billing cycle this not working.
i called toll free number to make complain to resolve this issue.
I said them dongle not working and
there is no network coverage,No registration, No Service.
What they saying is i have to check with outside of my house for coverage. For that i need Laptop or 3gsupport mobile.
I have only Desktop and Galaxy S3(support micro sim). I informed them.
But they simply saying there is no option to take this complaint before check these and said to buy some adapter to check signal.
I m using my airtel mobile in same house with same place have full coverage, i know signal is not the issue.
But they saying your 3g is active and you have to do these steps until they cant take complaints.
This make sure they simply plan to make bills only. I m sure next month i ll get bill without used dongle.
This is my bitter experience because i m using airtel broadband more than 4 years with fast solution.
I gonna disconnect my connection because i know they wont give any solution now.
Regards,
Alex