Shrek, first contact the hotel to see if the reservation has been cancelled. If its not then check that the hotel have been paid. More than likely its all cancelled and your credit card has been charged but the hotel didnt get the money. Also check on the 1800 booking email it should state some other company that will actually pay the hotel e.g. travco. Contact them also to see if the reservation has been cancelled.
If so then ring your branch, you will have to go in and fill out a "charge back" form and you will have to supply copies of the bookings and emails etc just as evidence. You will get your money back, I got mine refunded via NIB after 24 hours (with Mastercard).
If rebooking it seems hotels.com are doing some sort of 20% discount on rebookings for 1800 customers, you need your 1800 booking ref. Personally I rebooked directly with the hotel, I think I have had enough of these internet based intermediaries.