So let's get this straight - a less than honest organisation could claim and charge for,say, a zero-timing of your engine but not carry out the all of the work or use correct parts.
As an owner it is my fault if there are things wrong that appear later and it is down to me to sort out the court case.
Our regulator, who we pay for through taxation and various exorbitant charges, is not prepared to take action or help, but considers we have the responsibility, even though we are not qualified to do so.
Scandalous, and, I expect, would not stand up in court