Welcome to the forums. Your situation depends on whether you broke it or if it broke from normal usage. If you broke it then you will have to pay.
If didn't brake it and you just got your MacBook Pro then it should still be under warranty and they should fix it for free. Also if you are within 14 days of your purchase and you bought it from Apple then you should be able to return/exchange it. Take it to an Apple store and they will give you a final answer.
Well it sounds like Best Buy sold you a defective product. I'm not a big fan of Best Buy but I'll keep myself from getting off topic.
I just got it out of the Box with no V key and best buy told me that it was my fault. I have come to terms with the fact that I'm paying the bill just want to know how much it is going to run me.