Personally I think you have been reading to much Joe Polish.
Giving away 5 hrs Free Cleaning.
Did you investigate the second visit.
I think you should pay up.
You seem to be avoiding all responsibility for staff, so why not put and exclusion clause in your cleaning contract regarding breakages.
I thought under your employment system the customer pays staff, if this is the case that makes them the employer///?

?
If this is the case the customer would be responsible.
I sincerely advise you to go to a solicitor and have them give your business a legal health check
PS I'm not usually this blunt but I do not like your Web Site.
I do not like its name.