Can't unlink Origin account and Steam account

Hi. I don't use forums, so I apologize if this is formatted awfully.

Last night when Apex Legends was released on Steam, I accidentally linked the wrong Origin account to my Steam. I figured that it would be an easy fix, just go into my Origin account and unlink it, but that wasn't the case. First, I contacted EA help to try to unlink the two accounts. After waiting a while with false hope, I found out the person who was helping me could not unlink my accounts.

Let's call my main account "Account A" and my second account "Account B" to make things simple. I am posting this on account B.

As far as I understood, because I played Apex on account B, they couldn't unlink the accounts because it could mess with the game. Account B is only level 5, and I made it to play with a friend who doesn't play FPS games because I didn't want her to be in lobbies with players who spend most of their time playing the game. I was told to continue playing on account B, but the thing is: account A is level 300+, with limited time cosmetics and every single premium battle pass, along with every character unlocked. I'm not going to simply throw away that progress.

So, my next solution was to delete account B entirely. Surely if I completely delete it, it will unlink the two accounts, I thought. Someone from EA support called me, and informed me that even if the entire account is deleted, the two accounts will continue to be linked. He told me that they have been getting a lot of inquiries about this issue, and that at the moment they do not have a solution to this problem, but may have one in the future. He recommended posting on the forums, saying that it may speed up them working on this issue. So here I am, making a post on a forum I've never been to.

Just to be clear, I don't care about the progress I've made on account B. I don't care about Apex Legends on account B. Account B could be completely deleted and I wouldn't care, as I don't use it anymore, and only played it for a total of maybe 1-2 hours. No other games are owned on account B. For the time being, I am continuing to play Apex Legends on Origin on account A, but I would much prefer to play on Steam, as it is much more convenient for me.

Please, come up with a way to unlink these two accounts. The first person I talked to recommended I talk to steam support, but when I went to look at help specifically for Apex, they said they cannot help with games from other platforms or something like that, so steam cannot help me. I feel like it should be as simple as going to your account details where it mentions your linked accounts, and clicking an "unlink" button, as many other platforms have. Thank you for reading this if you have, as this is my last resort to getting my account unlinked.