I was on clearcraft (a server) playing a game called Infection and i quit to do something. I came back and I cant login because It says I can't do that while I am playing infected

You are my only hope for solving this because the server will not tell me the name of their site as I can only be on for 10 seconds of sitting at the lobby before I get a login penalty

Please help I'm having an emotional battlefeild and my head is about to explode from it help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!