Generally it is not a good idea to accept a repair or replacement on eBay. Not only is it unlikely that the seller can improve on the original*, but more important, you run the risk of getting past the 45 day deadline for complaints under eBay's Buyer Protection Program.
Since you are a new member , allow me to go over that for you.
If there is a problem your first step is to contact the seller. Most sellers will ask that you return the unwanted item for a refund (or a replacement). You only want a refund**.
You return the item with Confirmation of Delivery and he refunds your original payment. Some sellers will also refund your return postage but most will not.
If he refuses to cooperate on this, and don't waste a lot of back and forth, you go to the Resolution Centre (up on the right under Customer Support) and open a Dispute.
If he does not refund you himself, Paypal will and then go after him for the money. There are other penalties for him.
BUT
If you can't show that he has the unwanted item back, PP will not accept your claim. That's why you need the Confirmation of Delivery.
NOW
Did you used a Delivery Confirmed service, like ExpressPost? If not, PP will not help you.
Did you file the Dispute within the 45 day Dispute period? If not, PP will not help you,.
HOWEVER
You can still go to the credit card you really paid with (PP is just the mediator) phone the 1-800 customer service number and ask the clerk about a chargeback.
Write down all the dates, transaction numbers, payments etc, to help her process your refund.
As you can see, we are not allowed to name and shame other members on these Boards, so the mods removed the seller's ID from your post.
You have 60 days to leave feedback. The most effective feedback is calm and factual.
At the same time you will be asked to leave Detailed Seller Ratings. These are more important. The lowest Rating is ONE star. (No stars is a free pass). If a seller's stars go below 4.3 his ability to list and sell is extremely restricted.
* Unless he is also a full service B&M merchant.
** If you are actually happy with the seller, you can reorder later.