It proves what you said is wrong. You said its nonsense and that they will not respond which is just flat out not correct. Its not nonsense, they do respond and they do follow the rule. If its not legal then why do they acknowledge the common law right of land access? Why do they respond to requests and respond to the withdrawal of common law right for TV Licensing's officers to approach your property?
As for no injury so not trespassing that is incorrect. After injury there is an or which goes into especially to enter onto another's land wrongfully. There is a difference between knocking on someone's door and knocking on someone's door when you have clearly told them they have no right to come on your land. If you tell someone they are not allowed on your land and to get off and they still come onto it you are in a far stronger position as they cannot use the reason they did not know they where trespassing.
It shows I was wrong about their response to it, yes.
And I did admit that it might make you more hassle than you are worth to continue pursuing.
But you telling someone they have no right on your land does not change the fact they DO have a right on your land for the execution of their job. And regardless of a letter saying you don't have a TV, in no other circumstance of licenced property is suspicion of ownership content with "they once said they didn't"
I've looked (albeit briefly) and can find no ruling where a homeowner has revoked access and then won in court. I'm sure enough Freemen have been taken to court over it, so for you to say 'common law' it much have been ruled as such to be valid. Do you have a case/name/judge I can look into?