ShadowAssassin

Hi, me and a friend we decided to download GTA San Andreas to play online on MTA, it was literally my childhood and I really wanted to let him try it, unfortunately for some strange reason he was banned from any server without ever playing, I can assure you that he had never downloaded MTA before, he has already tried to uninstall the game and reinstall it but it doesn't work, what does he have to do to get unbanned?