I just purchased a new 2007 car and the next day a friend to me I
could have used his GM discount.  do I have the right to terminate the
deal or is there any grace period that a car can go back to the
dealership if they don't want to honor the discount.  I live in ga and
I know I can use the discount I just dont know it there is such a
period

If you read this on time, call a lawyer!  most states have between a
24 and 72 hour period.  I'm inclined to think Georgia does have such a
period too.