I paid for a years insurance up front. I had my insurance cancelled and did not receive notification that it had been cancelled till a week later, so I had been driving an uninsured car for a week.
They said it was cancelled as I did not forward information i.e. council tax bill and a few other items as they were doing an audit.
I did not receive an email for this but later found it in junk mail.
I then had to reinsure immediately and paid considerably more with different insurer. Validations were unhelpful and there attitude was basically tuff.