EDIT -9/4/19 11pm.. created a new account with new sim and new email and it worked.
also can't use referral AND code. one or the other.
it didn't work for my new account to which the email was sent.
may work.
i doubt it.
I'm wondering whether these codes are created/published so that people start new accounts to utilise the codes (which don't work) but Heyyou get bolstered numbers
This didn't work for me :/