Steam unlink via different account

Hello, I'm currently having technical issues regarding my steam account being leaked to a different account that for one, I do not have access too. It was linked a while ago and now, I'm trying to take it off but I'm unable too because of issues with the person that has access to the account my steam has been linked onto. I can show you that the account belongs to me especially since I used a 2FA to log into my steam account that nobody has access too. 

The image below shows that I've contacted the person to unlink my steam, but they're not doing it. I can't do it myself due to the fact that when I go on the other members account, I need their email notification to be able to unlink it. Without it, I'm unable to do anything and I can't leak my EA account to my actual steam account. 

If there's anything I can do, please let me know. Thank you so much!