considering quitting ebay due to bad experience with a buyer

[2240di]

I am seriously considering giving up on ebay, I guess I am too sensitive as I have over 900 positive feedbacks and have been proud of the fact, I sold an item that I purchased as new late last year, I only opened tha pakage to make sure everything worked, it looked perfect to me without visible marks or blemishes, 10 days after sending the item by express post at my own extra expense I received and email tellling me the item was not as described with visible defects, I immediately offered a refund or partial refund their choice,denying that I was not telling the truth, the next thing they take a case out against me, I have agreed to a redund when the item is returned, my question to them was why did it take so long to contact me, and why take a case out when I had agreed to a refund, My next question is what can I do if the item has been returned with obvious damage that was not there when I posted it carefully wrapped in bubble wrap.I am supposed to notify ebay when it arrives and they will refund the money, I feel dissatisfied with ebay, offering me no protection from a nasty buyer who never gave me the opportunity to defend myself. I have been buying and selling on ebay for over 6 years, but am considering shutting down my account and going elsewhere.