I had pretty much exactly the same. A friend bought one of my products via my site (tea) and I gave it to him personally the same day. Later Paypal reversed the payment with zero explanation. I didn't receive a single explanation from them, or even a response to my emails. They have a practical monopoly it seems, and dont seem to care an ounce about customer service for merchants. Let's all just switch to Stripe when they expand out of the USA!!