It's not like you paid for it yet, so I wouldn't call it 'fuct'. Give the seller a few days (7 is acceptable). On the 4th day, let him know that if he hasn't responded by the 7th that you will leave negative feedback. If he hasn't contacted you by the 10th, go ahead and leave a negative.
Or, you can request his contact information. Go to Help in the eBay tabs, and type "request seller contact". Input the item number and the seller's user ID and it will email you a copy of his telephone number and other information. Use this to reach him directly.