I’d say try again but specifically 1) talk to someone who is a designated GDPR officer (they have to have the contact listed), 2) specify that you don’t have an account, but are requesting the information anyway
Maybe just talking to a different person will get you different information. Most likely support is done by some center in India that is going by an internal faq and so it always depends who you gonna get.
I mean, them asking you to provide email/info of your account smells of misdirection already (whether deliberate or not), because you don’t have to have an account for them to have your data.
Recently I’ve been thinking of doing something about emails from a gaming store I’ve started receiving a few months ago, to an email I’ve not been using for over a decade and that’s only been registered to some forums. If I decide to look into that, they need to be able to explain where they got the my contact in the first place.