I sent them the redemption form, and today CS called me. It turns out there was a signup promotion when I sign up for the card. I forgot the specifics, but I do vaguely remember that there was one, and the reward is RM100 worth of cash voucher. 42,800 TBP can be used to redeem a RM100 cash voucher (e.g. Giant, Tesco, AEON, etc.), so that's why I got the points.