Boy some customers don't tell you.

[RoyM]

The shop I do some work for does the same. The customer is charged a half hour labor upfront or no service order. If a warranty claim is approved the money is refunded. If not warranty the deposit is included in the final repair bill. If the customer walks then at least the time is covered, happens frequently with hand held products. At least we don't have to dispose of junk with nothing to show for it.