I am using a Trinidad and Tobago credit card on a US account.
If you used your same google account to download anything from the Google Brunei store, they will not accept your payment.
I don't use VPN just opened a new google account with country setting US, that's how it did work for me.
Good luck
You can also open a new Google account and set the country to a place were you can join, like US or Germany.
I live in Trinidad and Tobago and there is no YouTube member subscription available, so I joined with a new Account with Country setting US.
So now a have a Google account for anything Yuzuru