I experienced a similar situation recently, on March 10. In the evening on March 10, I was playing on the console to complete the daily goals, the ones with daily play. At that moment I had 9.4 million coins in my account. I received a message from a user "EADominik", in which he tells me that he thanks me for playing FC24 and that I can get a reward, and his last message was a barcode.
I finish playing the matches, open the packs and after about 4 open packs I get about 3 duplicate cards and exit Ultimate Team from the console and enter the webapp to use those duplicate cards in SBCs, it's easier for me to do the SBCs from the webapp. I entered the webapp and the webapp was running extremely hard. I exited and entered again and I notice that I only have 200k left. I lost 9.2 million. I immediately notice that a player is being sold, a UCL Heroes Futre (I never had that player). It was sold at the market price from that moment, so we have a little over 600k in club.
I immediately come in to ask for help for a hacked account. After a few hours from that moment, I receive ban on transfer market, on March 11, then the next day, another one. After a few days, I receive an email telling me that I violated the rules of the game, that I distributed coins. I have only one account.
The next day I check more carefully which players have been bought. I discover a Heroes Berbatov at quiksell, a player I didn't have and didn't even want to buy. I also download my account details, that file from Your EA Data, where I notice that someone has logged into my account from two different IP addresses in Spain.
I appealed to the action, I am waiting for the answer, in the meantime I also requested a DSAR, and today I received an email that I will receive it within 30 days or the legal term.
I don't even know what to do to revoke my sanctions and return my coins. I don't think it was the ones from EA, so I think I would have been left with 0 coins in the club. How did you proceed?