While this is unfortunate, think of it this way...
From the other side, this seller doesn't know you from Joe Shmoe who may have called him for two weeks straight saying he wanted them, and then never showed when the day to do the deal occurred.
I think the real problem with deals like this is that sellers can't trust buyers to come thru with what they promise, as it puts the seller out more than the buyer does. So.... Take what is certain versus what is a maybe.
I can't say I agree with the actions themselves, but I do understand it, and I think you should too.