If I revoke a cable company's right to access my personal property via e-mail, are they still allowed to get on my property with the police?

You can revoke their ability to trespass on your property but not for they to get back their equipment, which is the only reason they would want to come onto your property. They certainly are allowed reasonable access to get back their property. The police felt the same way.

Yes, because you cannot revoke their right to be on your property. They are considered a public utility and there is an easement on your property allowing them access. So stop being a nuisance and let them do their jobs.