Unless you are dealing with a private seller and want to return the item simply due to the fact that you have changed your mind, then you should be able to get an eBay Returns Label sent to you by the seller so that you can return the item. You do not have to pay a penny for an eBay Returns Label - the label is paid for by the seller. Ask the seller via the case if you could have a refund if you return the item to him/her, as that way any reasonable seller ought to agree to refund you in full once you have returned the item to him/her.
In the event that you have opened a case but the seller is becoming awkward, or has stopped communicating with you completely, then escalate the case to eBay on the fourth business day after the case was opened. eBay will then step in and make a decision upon the matter, and in most cases they tend to decide in the buyer's favour. Therefore, if you do have to get eBay to step in they will more than likely issue a forced refund of the entire amount that you paid to the seller. Should this happen you would not have to return the item to the seller.
