Airtel 2 MBPS Plan - Stay away from it

I have been using Airtel 256 Kbps Unlimited plan for the last 6 months, the speed was okie and I should say I was happy with the service. Last week I decided to make a move to 2 MBPS connection plan (limited to 4 GB download). The change was done pretty soon but unfortunately I haven't noticed significant change in my download speed.

The customer personnel keeps asking me to check the speed in their website which keeps reporting download speeds around 1.5 MBPS - 1.7 MBPS. But if I try a different site like InternetFrog it keeps reporting a download speed of 400 - 500 kbps. They have sent a technician ?? to my house who looked and accepted that there was something wrong but went back and reported that everything was right???

I am not certainly not happy with the way Airtel is working to get this resolved.. but someday I hope to see Youtube videos without any pause :)

Update : It's been a month and my issue is still not resolved and I am frustrated after talking to Airtel Customer service for hours. So atlast I have decided to go back to my 256K unlimited plan. I am seriously looking elsewhere to change my ISP.