unlink working FC mobile account from banned many years ago EA account

When i was playing FIFA for PC many years ago, my EA account was blocked. I complettly forgot about it, and linked FC mobile account to facebook account. But that Facebbok account was linked to that blocked EA account. So now i can't access EA account for my FC mobile account. I just wanted to redeem halloween code and couldn't access ea account. And there is no option to unlink it myself and link to other EA account. Can you please help me with that ?