@klausryzenson The system might of detected the abbreviation as a bypass to the filter or that player had reported you back, (perhaps both happened). You should go to help.ea and create a case about the problem and include the video evidence if you still have it, as neither other players or EA fourm Admins are able to help you here.
I also recommend not saying anything in text or voice chat towards toxic or rude players in the future as unfortunately a lot of players just bait and flame others into responding back to them, and then those toxic/rude players just play the victim card because they think it's funny if they can get someone else banned for reacting to them.
One other thing is that if you get unbanned, change the chat setting to either "no one" or "friends only". It doesn't always work, but it will block 99.9% of these kinds of people from ever being able to insult you in the first place.