Send a team of apprentices without certified plumber

This company was appointed by Momentum insurance to fix a burst pipe in our shower. The owner send three apprentices without certificate and without a qualified supervisor plumber. Once they have started breaking the wall it was apparent that they lack expertise for such a job. Upon contacting the owner, Garry, we were told that he does not agree that a qualified plumber needs to supervise apprentices since their expertise is good enough. This is extremely unprofessional approach and contravenes regulations.