One minute fully booked and extemely happy then next minute booking falls through

As we only got back from visiting Matthew in France on Sunday night I was delighted to get a booking for 4 workmen for 4 nights on Monday morning. Any bookings at this time of year are appreciated so to be fully booked was amazing. About half an hour later the secretary rang me back to ask if I could put another workman up on Tuesday. Usually the triple rooms are occupied by a couple and child. On occaisions when there have been 3 singles travelling together I have made up the king size bed with two single duvets.  I suggested this set up but un fortunately that wasn't suitable so I lost the whole booking........very disappointing. That coming on top of having a 4 night booking for two workmen about two weeks ago who after telling me they would arrive at 4.30 didn't even bother to turn up or let me know till I contacted them at 8pm!! Luckily I haven't had too many situations like that but when it is your only booking it's rather disheartening.