An Error that Support Can't Even Help With

So, I have exhausted all my options, I have contacted support multiple times over many years, and I can't even get a response or any sort of help as they just tell me that this is an old game or that they can't help with this issue. The closest I got was a person who ended up giving up and telling me to post here. So I am now. 

This error focuses on the Sims 3 website specifically, and on redeeming a code/store function.

In short, I have had this error specifically below. I log in to my account on the Sims 3 website, I then try to redeem a code for two worlds I got in a bundle. They gave me the codes, but, I can't even get into access to the page to redeem them. It always returns this error.

I then decided to test if this was an issue across multiple accounts: I created another account using a burner email, and tried to go to redeem a code. IT WORKED. I could get into the redeem a code page. So I tried logging back into my main account and IT WAS BROKEN. For some reason this error is only effecting me. This was confirmed for me when I also asked support about it, and he said it worked for him. This error is not specific to a machine, or to a browser, or a location. This has been happening regardless of machine, regardless of what browser I use, and regardless of where I am in the world. This has been going on since 2023 when I first created my account to play sims. I have no idea what's causing it, and support doesn't understand either. I must assume it's an account error because it's only this account, and I have no idea what's causing it or why, as, clearly, my burner account works.

I got told to post here, so I have, and I don't know what to expect, or what help to get. What can I even do at this point? I just wanted redeem my two worlds and my chocolate fountain. :(

Anything anyone can help with would be appreciated. See the error below. Thanks for reading!