Looking for help from devs

I have reached out to Epic via email multiple times to no avail. Here’s the situation.
My son was 9 when he created an Epic account. He doesn’t recall his email and never verified it, because he’s a kid. Over the past 3 years, he’s accumulated a lot of stuff via purchases. He played on Nintendo Switch.
His switch broke. So we decided to connect his epic account to the Xbox and he could continue playing that way. I logged into his epic account to do so.
When I tried to connect to Xbox, I was asked to verify the email. This is of course the email account that he doesn’t remember.
So we went to the account information to see what email he used and to my surprise both his email and his own name are masked in his own account.
Therefore he can’t do anything and he has lost everything he has.
I’ve tried multiple times to explain this to Epic and I just keep getting stonewalled that we are out of luck if he can’t remember the email. I can’t find a way for Google to help and Nintendo was very nice but could not help.
Can anyone advise how to remedy this situation?