We all suffer this kind of thing occasionally, personally thankfully rarely, but it does happen.
Sounds like the price was on the high side if it could still be done in the half day remaining, when the Tech was there, or should I say Very high side.
It is a fact that when charging very high prices to average domestic customers, you can expect to have an above average number of cancellations and no shows. As this case shows it can also happen with above average domestics too. Purchaser remorse is a powerful emotion, which can lead to otherwise reasonable people doing unreasonable things.
Dave.