Just to add.....
Obviously, if your car number plate has been cloned, you would not have received a PCN for a parking contravention, it would have been put on the criminal's car.
Important point is that in order to submit reps that explain the cloning, you have to get back to the PCN stage, hence the submission of a Witness Statement. Puzzling why the Notice to Owner wasn't received.
Some advice - never ignore things like Charge Certificates or any PCN for that matter, because if you do it will come back to bite you as you could lose all appeal options.