Free credits is impossible, as they use some intense encryption, by sending simple client side scripts, you can make it look like there is credits, bu truthfully there is not. Back when you could scritp using photos i would scam players by adding the credit packet into the photo, so whne the photo was opened the user was tricked into thinking they had recived credits, thus giving me furni. But because this was only client side, if they tried to buy anything, it would not let them, and if they logged out obviously the client side packet thye saw woudl have disappeared.