Q: how much is a timing belt and what is the usual labor cost, told it would take 4 hours?

Tire plus had my car ALL DAY, received a call at 4:00 p.m. asking what were they suppose to do with my car? The store manager was gone (he took care of the work order) is it appropriate to ask for a discount? and how much of a discount. They were very unprofessional. This is the 2nd day they have my car.

My car has 69000 miles.
My car has an automatic transmission.