Can't Trade and False Positive Ban Message

I haven't been able to trade or put anything beyond magic quality in the guild bank since I've started playing. I always get a message that says that I have to reach level 25 before I can do so, but I have 3 characters level 35+.

And yesterday (after having not played for a few days), after playing for about 15 minutes, I got a message that said that I was banned by an administrator and was returned to character select but I was able to log back in and play without issue. I haven't cheated at a video game since I was a little kid using a game genie on NES back in the early 90s. I think cheating is lame and ruins gaming. I would never cheat.

Why would I have been flagged for cheating randomly, or... was someone trying to hack into my account by giving me some kind of fake ban message?