I was accidently banned on a promoted chat yesterday, and I asked my friend to ask the staff to unban me.
I logged into my computer when they unbanned me and it worked, then I went back to mobile on the same chat I was banned at and I was still banned anyways.
I find this a major bug because you might get banned sometimes for things you didn't mean to do.
Step 2. Ask a friend or staff to unban you
Step 3. You will still be banned