Whats the problem with my internet connection?

[Chitrarth]

I use a 6GB airtel 3G net dongle, I purchased it in the month of November when its performance was perfect. But then after a month, the postpaid number which I was using for my dongle was suspended for a reason and the company replaced the sim for me. Now, the problem started when I was given this new sim card, first problem is that I am not able to check my usage for my number (data usage-I.e, the data out of 6GB which I have used)- I click on the send button (send message to customer care for checking usage) and then the button is blank and it stays like that and no message is received or sent through this number. I can not make any calls to this number or call anyone from this number and the internet is a bit slow now and when I play online (through my PC) the game lags a lot and my latency is a lot higher than it normally is. While I tried another sim in my dongle and it is working perfectly alright (sms and calls are still there while in dongle). I have a complete doubt that the sim is not working properly. Am I right, or there might be any problem with the game (lags which occur while playing)?
Please tell me whatever you know.

[Animesh]

I think you are right its SIM problem...........................