You say your father made reps in May.
IMO, rather than stay on the back foot I would write to the council...
Dear Sir,
PCN **********
On ** May I made representations against the above by ***(the method used).
I have not received a reply but instead have received a Charge Certificate.
Procedurally I am now obliged to submit a Statutory Declaration, however, I should none the less like to know on what basis you have issued the certificate.
Hugs...
IMO you should also chase up your correspondence with the police, after all you might need their confirmation.