To try to fix this, you can try:
- Clearing your cookies and cache which is explained here, then either (2) or (3) depending on the device you are using
- If you are on a phone, restart it or flick airplane mode on then off again. Try accessing chat again
- If you are on a PC running Windows, Go to Start, type cmd and open the Command Prompt. Type ipconfig /release and press enter
When it's done its thing and you can type again, type ipconfig /renew then hit enter. Try accessing chat again
- If none of the above works are you are able to access your internet router you could try restarting that and trying again
- If all else fails, you will need to send your IP address in private message to the admin of the room that you are banned from. They can then investigate further.