Can't reset Meta quest password

My son has lost his password for his meta quest 2 and deleted the meta horizon app from his phone. When trying to log back in to the app on his phone I have tried the 'forgotten password' option, but this is not sending an email to his account (possibly due to his age). This means that we can't reset his password and therefore cannot get back into his account.

I have confirmed on his meta quest that the email is correct, yet no code is sent. I have tried to contact meta, but there is seemingly no way to do this. I can't even delete his account and lose all of the games he shas paid for as it won't allow me to re-register with the same email. 

I am now completely out of options, can anyone on here help?