Overcharging on Labour

They physically work on the vehicle for 45 minutes, the rest of the time they spend on their phones "waiting for parts" and then have the audacity to charge 2 5 hours labour!! It was just a few wires to the wiper motor that neede to be replaced yet they had to wait for parts!!!!!!!!! why not the just charge the customer for the time you worked on the vehicle. I was a return customer who will NEVER return again!!!!!!