1st booking with wrong nightly price

Hi,

Just new here and the calendars doesn't sync well with abb and I had conflict with this guest coming today. I just cancel the other one to start booking.com but the price was around $45 per day for an entire brand new home which is unaceptable. I sent a request of money to customer and no answer yet and email booking.com with booking id and no answer yet. The guest is coming at 9pm today and the extra money needs to be prepaid before check-in or it won't happen. Any phone number for USA hosts? 

Thanks,

Ralph