Did you ever set up his account in the new login system? Are you using the app or the website? Do you log in to your account on one or the other? If so then you likely need to clear the cache and data in the app or clear cache and cookies in the browser or use incognito mode.
You can use the forgot email link and enter his phone number and then look in all your possible email accounts for the email. Then use the forgot password link to reset the password.
In the meantime you can use a couple other methods to pay. 1. buy a voucher in lots of stores or online and dial 611 on his phone to enter the voucher. This would restart the account. 2. use real time payments in one online location or a few stores.
