Z. we're surprised and disappointed to find out your experience didn't meet your expectations. Judging from your response it looks to be a clear communication issue.
You were informed that a brake service (which was not inspected prior to your visit/ ie phone estimate) routinely runs $200-300 per axle. You were also told that if it needed calipers it could increase to the $500-600 range even though it was unlikely based on the description of your problem.
Your description was that it was making noise and vibrating when the pedal was applied. We found the primary source of your problem to be the front pads & rotors. The calipers were OK. The rears had material left on the pads but the rotors were warped. This is why we suggested front and rear brake services.
We did tell you $800 for premium brakes front and rear. You were also given prices of $640 for economy and $720 for mid grade.
You weren't pressured to do any work. What you did was approve the work and called back 20+ minutes later to say you changed your mind and didn't want to do the work. I asked why the change and you were extremely vague. I discussed options with you about ways to solve the probelm including changing the price if it was the option. This was an effort to not waste our time and to also provide you with a solution that wouldn't incurr any further costs. You declined, choosing to pay a nominal fee and to pull your car out. As a benefit to you, we actually had performed much of the brake service so that it would be simple and easy if you returned.
If you were only charged $150 that's likely due to 2 reasons. One the work we did to allow you to take your car mid service and two just changing the pads in the front. Not changing front pads and rotors or addressing the rear rotors (and or pads).
Hopefully this clears up your confusion and gives you better peace of mind. If you would have called and ask for an explanation I'm certain we could have cleared up any confusion. Good luck with your future repairs. Thanks for the opportunity.