Email support@mahjong.rsvp. It's a real inbox and a person reads it.
Include your board's web address — the mahjong.rsvp/… link your group uses. It's the fastest way to find you, and it saves a round trip.
You don't need us for that. Go to the reset page and enter the email that set the board up; a reset link comes straight back.
Ask within 30 days of paying and you get your money back, no questions asked. See the terms.