Murphy Motors Used Car in Raleigh, NC

I went to buy a car from Murphy Motor located in Raleigh, NC on Capital Blvd. I was looking at a 1999 Volvo with 137k miles on it. I was told that I would have to leave a $300.00 deposit on the car and come back within a week with the remainder of the $1500.00 deposit. Well two days later I went back and changed my mind deciding not to buy the car. I was cursed at and advised to leave the property and that my $300.00 would not be refunded! I spoke with the manager and he told me that he will not refund money that has been held for a car for a week. Needless to say, it had been only 2 days!! Isn’t there a law that allows a person to change their mind on purchasing a car within the first 72 hours? And also is it legal for him to keep the deposit? Even if it was less than 3 days?

Help,

David