I'm fairly new to selling, i had some digital keys i sold (15 of them). 13 buyers left positive feedback after redeeming them.

10 days later the last buyer who bought two codes did a chargeback through paypal. So the funds are on hold. The buyer has not contacted me with problems and even left positive feedback for one of them. 

After some investigation of my own i've noticed he's using multiple accounts all created within the last 30 days and is buying up all digital codes for Steam and GOG he can get, even overpriced ones. 

I have provided paypal with Images of the positive feedback and the email with the code in it. I'm hoping this is good enough.

To add salt to the wound ebay still charges seller fees for chargebacked items. Great!

I used to have respect for ebay and paypal but after this i have none. It seems like i dont have a leg to stand on when it comes to digital codes. The future does not look pretty for digital online retailers. 

Anyone have similar experiences with these types of cases of fraud? if so did you win the case or have any tips?