So ..
1) the buyer gives you positive feedback
2) then a month later, they file a Paypal dispute??
3) the buyer then admits that they've "damaged" the bag!
I find this disturbing on so many levels; I'm surprised that Paypal would even consider refunding the buyer! There should be a statute of limitation on the amount of time that has transpired (re: sale/receipt of merchandise)!
I had a (somewhat) similar situation sometime back .. also selling an LV bag (Denim Baggy GM Shoulder). It was a brand new/never used bag which my husband had purchased for me when we were on holiday in France. The buyer claimed that it wasn't "new" (obviously she was unfamiliar with the product because the Denim is supposed to look distressed) and then said it wasn't authentic (even though I had all the cards and had taken pics of the stamp inside the bag, etc.). Unfortunately, I didn't have the sales slip because it was a gift.
What really ****ed me off, is that Paypal took the funds out of my Paypal Account before any decision had been made! As such, I called them directly and asked to speak to a Manager. The Manager indicated that, in fact, a "hold" was put on the funds .. they wouldn't be distributed until a decision was made. I made sure to provide all pictures, etc. through the appropriate channels. Interestingly enough, the Paypal personnel noticed that the buyer seemed to have a history of "returning" items/filing disputes. More importantly, the Paypal personnel informed me that the buyer had to send the item back (using Tracking info) and that the item had to be in the same condition as what was sent to her!! Well, 'lo and behold, the item WAS NOT in the same condition .. it was obvious that she had used the bag! Since Paypal had the "before" pictures, I only needed to provide the "after" pictures where they could see that it was not in the same condition.
Mind you, all of this took about a month before it all got sorted out, but I persisted and finally won (I have been selling on eBay for a very long time and have 100% feedback). Bottom line .. the buyer only got about 25% back because it was obvious that she had damaged the bag. After all was done, I BLOCKED her on eBay!! Good luck!!!