Paypal has screwed me over many times. Recently a dishonest customer, who had the product for months, said I must either give a refund, or he'll request a chargeback. I refused, since he already had the product. So he did a chargeback, and told paypal that he never authorized the transaction. Paypal saw from his ip address at the time of ordering that he was lying, so they initially refused his refund request. I was happy with this.
Then the buyer's credit card company did the chargeback anyway. This left paypal in debt. So paypal then reversed their initial decision, so I would pick up the bill of a dishonest chargeback. I spoke to their staff, and showed them the buyer's threats. I asked them why they changed their minds, but the answer was clear.
Paypal are crooks. This is not the first time I was screwed by them. In this example, what they should have done is considered the buyer's threats, and explained to the purchaser's bank that the ip address of the buyer is correct, and the transaction was authorized. But they instead chose to screw me over, and this was a transaction of around $3000.
I will never use paypal again. Like any large company, they become complacent and dont give a crap about you, what is right, or what is fair