We hired a plumber to install a hydrant on the side of the house to water our garden. Under his advisement, we also had him install a relief valve on the well pump to make it safer. He finished the job and left. The water in the house pulsated with pressure changes and we were unable to run more than one source of water at a time. We contacted the plumber twice before he agreed to take a look. We were unable to be home when he could come out so, we requested he call us to advise us of what was wrong after he made some guesses over the phone. We came home to a new well pump and a bill for $566.19. ($390 for parts and $176 for labor). Do we actually owe him for this job even though the well pump was not broken before he made the requested repairs and we did not authorize him to install a new well pump?