BOOKING .COM IS HELL

i had booked for a weekend away from the 19-23 at barbados in cape town i made the booking yesterday and then later found out I have a crisis at home .i called them today not to ask for a refund but to move my days to a later month during the year they said still said no , an in their policy that a cancelation can only be done within 72 hours that's exactly what I'm doing but the still said no ,i want this fixed and now .