Client is freezing while choosing an champion

It happens everyday ! Always when i'm trying to pick an champ or ban an champ it's freezing and when the countdwon comes to 0 nothing happens. Of cource after some time, when it's my trun to pick a champ I get kicked of the lobby and get blocked for 5 mins and if it happnes two times i get blocked for 30 mins.... client reapair didn't work...