RE: I made a BIG mistake
I wouldn't worry about it. That's their way of showing good customer service. Doing business this way ensures your loyalty. And the money doesn't come out of their pocket anyway. They will ship the bow back to PSE as defective, who will in return ship them a new bow.
Now, take the $310 and get a good bow. Something in the Martin line. You'll be getting a much better quality bow for your money.