When you post the item out you need to post it to the address provided on the PayPal notification of payment e-mail so as to ensure that you're covered by seller protection. So long as you've got the remainder of the address right, including the postcode, then the item ought to get to the buyer's address. Ewell and Epsom are both very close to each other, so it could be that the buyer's address is right on the border of Ewell and Epsom, which could be what is leading to the confusion. I live a very short drive away from both Ewell and Epsom so I'm familiar with the area, and some addresses often get included as Ewell when they're actually Epsom addresses, and vice versa.
With regards to the postage labels don't bother trying to print them off of eBay. Just address the package and then buy the postage labels from the Post Office when you take the parcel down to the Post Office to be posted out, or alternatively if you have a supply of blank labels print a postage label directly from the Royal Mail's own website and then stick that on the parcel instead. If you use one of those alternative options when purchasing the postage label then you won't have to put up with eBay screwing up the postage label!
Finally, make sure that you post the item via a tracked method of postage and upload the tracking number next to the item in question as soon as possible after you've posted it, as if you've got tracking for the item you can successfully defend yourself should the buyer open a false Item Not Received case against you. If the buyer did try to do that but you were able to prove with the tracking details that the item had been successfully delivered then you'd be able to blow the buyer's allegations of non-receipt right out of the water, and he/she would not be able to leave you any bad feedback in relation to the transaction. You could also successfully get any negative feedback removed if the buyer did open a false Item Not Received case against you but you managed to win the case once you'd proved that the item had been successfully delivered to the buyer, and the associated defect resulting from the negative feedback would be removed from your account as well.
