How do I go about getting a refund on eBay?

item hasn't been shipped yet...finally heard back from the guy who said that his car is broken down so he can't ship the item right now.

I e-mailed him saying that if he can't ship the item by the 20th...I will need a full refund. The payment has already posted according to my bank account.

Should I contact eBay and Paypal?