Trying to unlink an unknown Steam account from my EA account

Hello, 

I recently gained access to my account after some time. Found out there's a Steam account linked to my EA account that is not mine. I never permitted this account or got an email confirmation for it.

I reset all my passwords and tried to unlink the Steam account, but it does not work. I tried linking and unlinking other platforms, and it seems the same. Seems the unlinking feature does not work. Can someone please help me?

I want to unlink my EA account to that unknown Steam account and link my own. I'm currently playing the Battlefield 6 beta on PS5, and when I get a new PC built, I want everything to transfer to my Steam account. 

Thank you.