Unlinking a Steam account I don't own

Today I bought three battlefield games on Steam and wanted to play, after downloading them I bumped into an unexpected message "The EA account is already linked to..." which is strange because I never linked my Steam profile to the EA one.

I thought somebody hacked into my account, so I changed my password, after that I tried to unlink their profile, went to myaccount.ea.com, there I spotted another account which is not mine linked to Amazon, tried to unlink both of them, after agreeing to the terms and... nothing changed, the accounts are still there, what can I do?