I sent the game account to the buyer, the buyer deposited the money to me, and I received the money. But the money is now held in my account. I looked it up and the buyer told me that I need to press OK on the confirmation receipt to use the money, what happens if the buyer cancel? I already gave you my account information and I can't get it back. Is it this a chance for buyers to scam sellers isn't it?
Firstly that depends on many factors all listed in Paypals seller protection policy for you to read so you can risk assess your transactions. Legal (bottom right of Paypals pages) > user agreement > seller protection.