Lewisburg Plumbing & Heating

My pipes broke a few weeks ago and decided to give this business a call. I called friday evening when I got off of work and was told they would come out Monday because they don't work weekends. It seems stupid to me to have a heating and plumbing business that is not seven days a week.
I said ok and asked when they would arrive. She told me she didn't know when. I have a job. I can't tell them I need to stay home until a plumber decides to show up. I find a friend that will stay for me.
on Monday I call for a more specific time/update on their status. The lady tells me the plumber will arrive after lunch. I ask her to please be more specific and she tells me "I don't know... around twelve?" I call my friend and tell her the plumber will show up... twelvish.
They take from twelve twenty five when they show up to five after three. This included the time it took to drive to their where house to get a part.
They then demand credit card information. NOT a payment. Credit card informaion. When asked how much the charge was they said I don't know buthe I'm not leaving until I get it.
So if lewisburg plumbing and heating is hired, they DEMAND a blank check. NOT payment. (I won't steal from u. I'm a plumber.)
I call them to find out how much money they decided that they deserve. 90 per hour. Plus 25 for the part they had to go get. Also the clock starts running when the plumbers claim to leave their office... not when the START WORKING like every other business I have ever hired. The time ends when they get back not when they are done working. Thank god they could find my house or I would have owed them a fortune.
Charging customers for.the time it takes to go get a part? Why keep any parts in your van at all if you force the customer to pay 90 bucks an hour for you to drive to your where house and pick the part up. It's not like they can argue... you demand a blank check. I ended up owing 500 bucks for three hours of work.

How can a business operate like this legaly?!
I don't pay my mechanic for the time it takes him to go get a part.
Even businesses that have to travel to you don't charge u for it. (A wrecker, a cab, the hvac people I use)
I asked for explanations for the charges and all I got was an attitude.