No refund from Booking. Com

I booked for accommodation with booking. Com from the 2nd to the 4th of February. Within 10 minutes I realized that I booked the wrong guest house because the names were almost the same and I called the guest house and the owner said I must cancel and promised to refund me because it's not yet 24 hours since I have booked. I logged a request for refund until to date I haven't been refunded yet.