Ive seen this happen a lot more than I care to think about. Here is the scenario- you got your house sold and you have made a deal on the next house you are moving to and a week before closing your agent tells you that the buyer has walked. What do you do!!! You have agreed to buy another house- all your stuff is packed, the utilities in the new place are in your name, and the list goes on and on.
First off- when you the Seller get an offer make sure there is some earnest money with the offer- people are less likely to just walk if they have money on the line. The buyer doesn't get that money given back to them unless you say they do- but hey on the other hand you don't automatically get it either. Most of the time in this scenario neither buyer or seller will sign a release- so the money sets in my trust account for 3 years then the state of Iowa gets it. This is not my decision ITS THE LAW.
As the seller you do have the option to sue for performance. The buyer and you entered into a binding contract and that contract states that a buyer can't just walk for no good reason. I always remind people to keep a level head and try to work out the problem- nobody wants to go to court- and there must be some kind of problem or the deal would have been completed.
The only place a verbal contract is no good is in a real estate deal- everything has to be in writing for it to be valid.
Usually when the potential buyer realizes that he/she is going to be sued they might decide to complete the deal and if they have put a large deposit of earnest money on the line they will think twice before walking. I usually see this when there is little to no earnest money put with an offer. As a seller I caution you not to request a HUGE amount for earnest either- many buyers are scraping up all of their savings for this purchase anyway.
If the buyer was ready, willing, and able to buy, a judge can force them to continue the deal- but again that is a lengthy process. People are people and if I could control them I would be in a different line of work. I, just like you, want the deal to close but I can't make anybody do anything (funny how people are like that) This is where we become worth our weight in gold as myself and the other agent work to get this deal to closing and not left hanging in mid air.
Hopefully you will never have to go through this- talk about the stress!! For the record screaming, yelling, and throwing things doesn't help there is an immediate problem that needs adult attention to make everyone happy