Asked for refund through PayPal after I sold the account.

I sold the account 2 weeks ago everything went smoothly. The money this person sent me was taken out of my account recently on PayPal which has left me with a negative balance. He asked PayPal for a full refund after I sold him the account. He claimed that he never received the account to PayPal and said to me that he lost the account. I then tried to recover the account from the games support and it turned out that the account was suspended for suspicion of using a third party hack. I was able to recover the account as a one time courtesy due to it being used from a different IP/country and they thought my account was hacked. He then said he would like the account back and I refused and then he left me a negative review.