My condolences on the loss of your Dad.
You have every right to annoyed, looking at the above we are also annoyed that a person claiming to be a member of our trade has abused the trust placed in him, prices and hourly rates vary but even a surgeon holding a persons life in their hands would not charge that much for a few minutes work.
There are very few options open to you that may bring satisfaction, I know locally if such a thing is reported to the Police they can't do anything about what we consider criminal however they do tend to make the offending parties life very difficult in other ways.
All I can suggest is that any action you intend taking please keep it within the law, citisens advice or your Solicitor would be much better than me to advise you on any further action you might take.