If it's any consolation, the sellers may still be on the hook with the selling broker for any expenses the broker incurred unless the house was a FSBO (For Sale By Owner).
Once a broker has a buyer and the seller changes their mind, the broker is in a position to recoup all of his/her expenses incurred in marketing the house.
If you really wanted this house, keep in contact with the broker. It's possible they may change their mind. However, be careful of people like this. It sounds like they are all over the map.
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Armand