I just treat their letters as scrap paper or kindling. They are very carefully worded to give the illusion of power where there is practically none. Capita are masters in mismanagement, so I’m not surprised your declarations have been ignored in the past. Just don’t bother.
If you’re truly not doing anything required to have a licence, then they can’t prove you do. Licence dodgers are usually clever enough to not give it away too.
Don’t answer the door to them on the rare off chance they come prospectively calling. If you do, just close it on the scum without a word, and go about your day. No warrant = no entry.
Back in the day it just worked because you bought a card with a supported chip… or you had to do some ungodly things with ndiswrapper to get the Windows driver loaded.
I think back then I was using wicd as well.
It’s come a long way.