Good answer, chris - that ought to be on the eBay site!
If the buyer says they don't accept returns, unless of course the item is faulty or not as described, then they don't accept returns. Why should they?
The original listing will still be available for you to look at, if it had been changed after you'd started bidding on it, you would have been alerted to this.
Why didn't you check before you bid on the size of the face? It's not the seller's fault you made a mistake.
I don't see why you should be "sick and tired" of buying on eBay on the basis of this, which is your error, not the seller's, according to your description.