Question regarding a repair I had done on my vehicle

Before taking a 750 mile (round) trip, we took the car to get the oil changed. Part of the oil change is topping the other fluids. When the mechanic's shop was done we had errands to run. Keep in mind it was a wet day; drizzling, not raining. Back to errands: the post office, 6 miles from the shop, we heard an unfamiliar noise as we pulled into the post office parking lot. When we got out of the car we smelled something, open the hood but the smell was gone - we thought the smell must have came from a different car. We went home (six miles again). About thirty minutes. Later we drove to the store (one to two miles) and came back home. Later we left again, after about one mile the car's warning started dinging persistently, we pulled over immediately. The gauge was fully to the red (hot). It was night, the street was very dark and we only had the flashlights on our phones. We decided to skip the errand and go back home (one mile). We first let the engine cool and drove back home very slowly. We pulled over and turned the car off half way home to let it cool down again. When we got home the dashboard (finally) read "engine coolant too hot" (or overheating) so we opened the hood and saw that the coolant tank was empty. We filled it with water. In the morning we took the car back to the shop. They said the water line (?) Had a leak. I do not believe that. I think they drained the coolant/water tank and forgot to fill it back up (it was 5:30 p.M. Closing time when they were done with the oil change). So now we have a quote for $250.00 plus they have to keep the car overnight.
Keep in mind we just wanted an oil change before taking a trip. There were no problems with overheating nor coolant leaks. The only service required, prior to getting the oil changed, are to service the traction, ABS and stability systems as indicated on the dashboard. We were going to do that at a different shop.
Sorry this is so long. I just do not want to leave out any pertinent information. We have had the car three and half months. It had no problem moving us from CA to AZ hauling a large trailer. The previous owners have been car dealerships. By looking under the hood you would never guess it is a 2008 it has been well maintained. Anyway, I was charged $357.52 for what I believe was their fault.
Was I scammed? I would upload a copy of the receipt if I could, but here is the breakdown:
Remove and replace water pump $95.86
GMB 130-9660 water pump $85.00
Disposal fee (antifreeze) $2.00
Anti-freeze Dexcool Red GM OEM $27.99
Labor discount -$25.00
Remove and replace hub assembly $62.00
Shop supplies $3.00
DHA 29513236 Hub Assembly $89.99
Subtotal parts $207.98
Subtotal labor $132.86
Tax 8.100%
Total $357.52