I don't believe you were too quick off the mark at all. If you bought & paid on Sunday, then I would definitely expect a seller to have been in contact about pick up by the Thursday.

There would be very, very few reasons why they could not be in contact or reply to messages. These days just about everyone has a phone or ipad or laptop so even if their own device was down, they could use someone else's.  Unless they were carted off to hospital (fairly unlikely) then there is no excuse for a 4 day delay.

You have raised a dispute, just follow through with that. You won't get the seller details as in their phone number, if that is what you were after, but you don't really need them. You will get a full refund. 

Or.. the seller may respond to the dispute and get in touch with you and you can go from there.

But sugar is right in that you shouldn't close that dispute till it is resolved and you have either the refund or furniture in your little hot hands.

Most likely a bit quick of the mark to open a case,  but fair enough if thats what you want to do.   Now just follow the instructionms from Ebay,  dont close the case till you get a refund.   No need to converse with the seller.

But on them not replying there are a multitude of reasons why they havent (illness,  internet, etc),  but at the end of the day the power is in your hands to open the case as you have done.