Sorry to hear about this! That type of behavior is absolutely against the spirit of the game and is not something we find acceptable either.
There is now an option in-game to report players for Teaming so we can take a closer look at the situation with a bit more data from that particular timeframe. That's going to be the best way to bring this directly to the attention of the correct team if you should run into teams doing this. Once you open the report option in-game, this option is under Gameplay Disruption > Colluding With Enemies.
If you have additional information to pass along or are otherwise not able to use that reporting option, you can also report that with the form here: https://help.ea.com/en/help/faq/report-players-for-cheating-abuse-and-harassment/#eahelp
I've edited the names out of your post per our forum guidelines, but thanks for taking the time to bring that to our attention.