I paid a deposit of $450 for a car from a private seller on Gumtree 4 days ago. We agreed to pay the balance upon pick up. However, due to a family emergency, I am unable to pay the balance and have not picked up the car. I called the seller advising of my situation and asked for a refund of my $450. He advised that he will not give me a refund unless someone else buys the car. Also that he will readvertise etc. I feel I am entitled to a refund as I have not even received the car. Please advise on what my rights are.