I have been banned without any reason and cannot find any ban records.

As far as I know, such problems are not rare in Chinese Mainland, at least hundreds of people have been affected. Some of them were even informed that they had been banned before playing Battlefield 6. 

I pre ordered the Phantom version of Battlefield 6 and also pre ordered the Tombstone Squad version of Battlefield 2042, which I firmly supported during the most difficult period of the series. However, I have been banned for no reason now, and the eahelp webpage cannot even create work orders. The window for practicing human customer service has also disappeared. I don't even know how to give feedback on the problems I encounter. 

And, I haven't even played much in the multiplayer mode of Battlefield 6 yet. During the 20 hour game, I spent most of my time playing campaign and portal modes. I don't understand if I did anything that violates the game rules?

My English is not very well, so If there are any inaccuracies in my expression, please forgive me and tell me.