Someone made an account under the email I'm using for said account?

So I got an email saying someone had made, and verified, this account using my current email address, naturally I made sure to change the password to this account and all its information, but... I don't understand the motive? Were they waiting for me to log in so they could get my details on the off chance I didn't change the password? To be clear, I did not make this account, it was made using my email and I'm just trying to stay logged in till I know what's going on.

I'm not sure what to do about it, are there any other security measures I should be taking here? It's not like they had access to my payment methods or anything, I'm really baffled and concerned.

I also changed the password for my email of course, it did scare me that they managed to verify the account somehow, but there's no new logins detected on gmail so I have no idea what's going on.

Also if it matters, the email address I received all this info from was mailto:EA@e.ea.com, I wasn't sure if it was legit so I made sure to only log into the website itself, wasn't gonna risk falling for a phishing scam.

So yeah, any advice? Should I be worried, should I be doing something else? I appreciate any and all help.