I unlocked to add this:
Some silly [selfcensored] abused the webchat, and there was around 15 bans, all the same user and all webchat. You personally haven't been banned, you just need to download a client.

If you can't/won't install, then I suggest using a portable client.
http://portableapps.com/apps/internet/kvirc_portable
http://portableapps.com/apps/internet/pchat_portable