I won an item on ebay 4 days ago, seller said cash on collection only.

Any how I won item, now seller will not respond to any messages I send asking for address, I have his contact details, but phone just rings out, I requested these details through ebay, but for some reason, my email address was relesed to him, but not his to me.

What can I do?

At least you have not paid in advance,you could raise a dispute with Ebay, naughty of them to release your details,

Do they have any feedback? Check what the comments are.
They could genuinely have forgotten they were going away for a few days - I have done that before today. If they don't respond in the next day or two - try at different times of the day - then report them to ebay. I think that's all you can do as no money has exchanged hands.

did it say anywhere in the advert that the seller would be away? sometimes i know i put in it "won't respond until such a date as i will be away" or words to that effect to inform buyers and cover my arse from any ebay cases.

i'm quite an avid ebayer but never been in your situation so i can't really advise otherwise sorry.

maybe check the your order details and look for any further contact details there...

Go to the the Resolution Centre on your Ebay account.
Here's some information that might help
If a seller doesn't reply to your email, call them. You can find their contact information using advanced search. Keep in mind, you can only get another member's contact info if you have a transaction with them. You'll need to provide the other person's user ID and an item number from a recent transaction.

When we send you their contact info, we'll send your contact info to the seller at the same time. If their phone number is wrong or not working, contact us to let us know.

If the seller doesn't respond or doesn't complete your transaction, we recommend opening a case to report the problem.

They are under an obligation to sell you the item however if they choose not to because you won it for less than they were expecting eBay will only give them a "strike".

3 strikes and they are banned iirc.

I tend not to buy anything unless I have had contact with the seller beforehand.
There are a lot of idiots on eBay these days and all eBay seem to care about is getting the money rolling in, do they have any other items for sale?
What is their User identification?

There are ways of finding them, just don't leave bad feedback until you know the circumstances.

When buying I like to collect ASAP so I contact seller beforehand to let them know, sometimes this isn't a good move as it can show the seller your more interested in an item and it can induce shill bidding.

Ebays not really as good ad it used to be, too many assholes and scammers.

Good luck.

I had exactly the same thing happen, a guy in Coventry who just dropped of the world when I won.
Ebay, bless them, said that no-one could force them to sell. I asked them about breach of Contract, still refused to act.

Same here, I won the item, paid by Paypal but never received it (which was an absolute bargain I have to say!) Seller claimed it had been sent then changed their mind saying it would be sent after I asked for proof of posting. Long story short is I raised a case and was given the option of having the item sent or money refunded.I chose the item but the seller refused to sell (as it was much less than she wanted I suspect) so I left my first and only bad feedback which she wanted me to retract! On checking her feedback a few days later she had made something of a habit of this and again, EBay stated they could not force anyone to sell the item! I'd steer clear and be glad you haven't paid as yet!