I have had an horrendous experience with persimmon which I am more than happy for you to use as a case study. My house is now 9 months behind in completion with no communication.
After promises from everyone including the MD we were ready to complete today. Persimmon called me at 3pm yesterday to inform me the house is not ready as there is no steps to get to the front door. So inless that 24 hours to completion this was noticed which has left me in a very difficult position as I should have been moving today.