Most customers don't have a clue on the cost to run a business. Their $25 for five minutes is $300 per hour...over $600,000 per year and that's all they see. Rent, heat, tool costs, un-billed time and so on are items they have no clue on.

It sounds like they had a little attitude about the whole thing when they clearly received great value for their dollar. Too bad for them, it sounds like they lost a source for help.