Tax Rebate

I missed filing for 2007 tax returns in USA. Anyway I took the W2 form to ask some one if I can do something about it. In a free time I browsed Turbotax.com and came to know that I can file for a refund before 15th October. Created an account in turbo tax and did e-file for refund. I was said that I would get a rebate of $300 too. But I am getting all the tax I paid back. How come I get more???? State tax was in my account sharp at the estimated date. Then federal tax refund was in my account another 3 days later. One week passed, the rebate $300 was in my account. IT REALLY WORKED. That is how taxation happens in United States. On the other hand I have not received my 2004-2005 tax refunds yet in Sri Lanka.