Dispute unauthorized charge on PayPal

I have an unauthorized charge for 500 dollars on my PayPal sent to a random person. I contacted PayPal about this and within 2 hours, they responded that they had thoroughly looked into the case and since this was a personal transaction, they could do nothing. I contacted my bank Wells Fargo and they mentioned they could stop the transaction but only for a fee. What can I do in this case and who should I dispute the charges with?