Bob,
The thing to do is send them an invoice back for your time, lost business and especially incorrect advice. The invoice should be more than £51.
When they don't pay then threaten to get the court baliffs on them.
OR go to the small claims court......no public advice of charges, no contract, no advance Ts&Cs, unfair contract terms, unfairly high charges, etc.
Do formally complain in writing about ignoring the other local companies with examples, inspectors name. Allege discrimination, ignorance of the H&S laws and cowardice in not confronting the other businesses.
Next time tell them to eff off as well.