AND, I wouldn't expect any refund either.
Many shops culculate their bottom line based on BOTH parts and labor .
You'll find that a shop who gives away their parts at strait cost DOES make it all up on the labor rate.
They may have also include many job neccessary items which were not itemized on the bill; ie; wire, splices, straps, tape, solder, screws, bolts, cleaners, retainers, etc.
So, knowing what the components could have cost, you decide if you paid a fair bottom line for the total job.
If YOU were doing this job for pay, what would you honestly expect ?