2 Day ban with no warning?

I was watching a duel and all of a sudden I get banned for two days
Having never received a warning from an admin, I can only assume I had no strikes.
I haven't the slightest clue which rule I broke, but looking over the ban table all the 1st offense starts off with a warning, 7 day ban or perm ban. 2 day bans are only given for 2nd-3rd offenses, did I receive a strike with no warning?

I logged onto another account to ask a mod for why I was banned. He accuses me of ban evading and refuses to answer my question despite the fact I said would log off immediately upon hearing the reason for my ban. Very helpful.

Can I please get an explanation?
DN id: ! heart of the cards