Yes coming to a shop can be a harrowing ordeal, especially when everything on the truck just doesn't work right. It makes it hard to stick to a price when you're told one thing by phone and the vehicle arrives and there's a lot more wrong than mentioned, at least finding out that there is.
We did stick to the $150 as you were only charged $142.50 for labor diagnosis. You had two shorted out sensors that had to be replaced just to continue to diagnose the truck. The coolant temp sensor and the oil pressure sensor. Because you are a valuable customer we did not charge any extra labor for those, just the cost of the parts. That includes fixing the broken stripped wire connector on the temp sensor for free. You seemed agreeable to that here at the shop or we wouldn't have charged you for the parts as they can always be pulled back off while it's still here.
As for the A/C, this is the first we heard about that. Bring it back when you can and we'll find out why it's not working for no additional charges again. Of course we value all our customers and we strive to make things right!