Airtel — Airtel Blackberry curve 8250

Recently I bought the Blackberry Curve 8250 from Hypercity, Malad. I have activated the GPRS on it but it is not working for some reason.
Every few hours I call Airtel customer service at 121 and for the past 4 days to solve this issue but I have been shoved from pillar to post and nothing has come out of it. The customer services guys (at 121) are not competant enough to solve the issue and tell me that the plans are available for my postpaid calling plan and that it should work. Then I get a call from technical support telling me its not available and to call 7070. The 7070 tells me the plans are fine and to call 121. I have been calling in circles, taking to Pankaj (at 121) to Tanuja (least competant person at technical support) to Aniket (Tanuja's sup) and many such people...nothing! My problem has not been solved. I even informed the customer service, Im ready to switch to any other calling plan at airtel but to no avail..they just dont know what to do. With number portability coming up, Airtel will be losing a lot of customers if they keep doing this. And the locked phone can be unlocked very easily.