Never buy Airtel 3g dongle and data card. Review on Airtel Data Card

I have purchased Airtel 3G dongle along with data card from Airtel relationship center at Sector-7, Rohini New Delhi, while purchasing I was promised that the network speed at Rohini will be around 6.5 Mbps even though the max speed 7.2 Mbps, where as other brand dongles are promising but cannot support beyond 3.1 Mbps.

I after trying my best with all settings and start guide instruction for a week I returned to the store that the connection is not giving more than 700 kbps speed, the customer executive told me to raise the complaint with customer care and representative will come to home to solve the problem, but even after several complaints no one turned up and the settings suggested through phone were useless.

After that I check my laptop with other dongles (Tata photon and Vodafone) from my friends, its working fine with those dongles. Then I went back to relationship center, then Mr.Amit at the 'May I Help You' counter says that the 7.2 Mbps is an advertisement stunt and no dongle will support beyond 2 to 3Mbps. but my dongle+ data card not supporting even 900 kbps consistently however  the signal strength is full.

The conclusion is never buy Airtel 3g dongle/data card it is only an advertisement stunt as told by their own relationship center employee, but to evaluate this I lost Rs.1500/- and a good amount of time.