Cant Join Ent dota games "new player ban" "Leaver"

[llcalimjll]

My friend bought the game recently and he cant join the Games.
He's saying he get the message "new player ban" "Leaver blah blah blah"
How can He fix his problem. My other friend just bought the game also but he can join any of the game fine.
HELP ME or Help my Friend OuT GUYS!!!!

[uakf.b]

Your friend must have left a game? Please have him post in ban appeals.