In my opinion the best way to survive an eBay dispute is not to have one in the first
place there some simple things you can do to accomplish this:
Respond to all emails that the buyer sends you in a courteous manner. It's a good idea to say sorry and thank you even when you have done nothing wrong.
Send the item within two days and email the buyer with the tracking information. This will ward off many "Item Not Received" disputes before they even get started.
If you are shipping with a method or to a country that doesn't allow tracking then you are inviting "Item Not Received" disputes.
Once the item has been delivered according to the tracking information send a reminder email about leaving positive feedback. Once you have positive feedback it will be very hard for the buyer to win any dispute.
Describe your item truthfully, don't exaggerate.
Have a clear refund policy and offer a refund according to the terms set out.
Now let's say that you've done all those things and the buyer still opens a dispute. What can you do to make sure you don't end up on the losing end, do the following to give yourself a chance:
Go to the dispute resolution console and enter the tracking information for the item in dispute. If it is a "Item Not Received" complaint then this will usually solve the problem (assuming the tracking shows it was delivered).
If the dispute is more complicated then it is a good idea to enter all email correspondence between you and the customer (another good reason to be courteous).
Correspond with the buyer using the dispute resolution console eBay monitors the interactions and the buyers unwillingness to negotiate may go in your favor.
Try to reach an agreement according to your refund policy. For example I always state that I will give a full refund when the item in question is returned (at the buyers expense). Or sometimes I offer a partial refund if some part of the item was broken.
If you have any receipts to show the condition of the item scan them and enter them under "Supporting Documents".
These are just some simple tips and don't guarantee that eBay will rule in your favor they will however give you a better chance.