I would love to see the Consumer Protection from Unfair Trading Practice law used against the Dubs, but I think it is one hell of a stretch to get it to work in reality.
This law is designed to stop commercial concerns from exactly the kind of irritating marketing the poor guy in the news story suffered.
The WT would claim first of all they are not a commercial concern selling anything. We know that is a lie, but the Courts would have to use the utmost skill to uncover that, at the end, it is a selling scam.
Assuming you get over that hurdle, you then have to show that the same company cold-called you, and I bet the WT could call you on that, each congregation in their set-up is an independant to a great degree (when it suits them, and a lie anyway) so if a"brother" was visiting your Congo, but knocking where you live, he would not actually be from the same "Company". Do you know which Congo. the caller is associated with ? and so on Ad Nauseum.
Sadly, though this law in reality is designed to stop the JW's method of marketing, i.e bloody irritating cold calls, I think if you went to law you would have one helluva uphill struggle to make it work.
Nothing to stop you quoting it in a letter to the Elders though, in addition to anything else you wish to mention, the Human Rights Act, whatever, most Elders are legally illiiterate, if not illiterate in a general sense, and will shit a brick when you threaten action based on several Acts of Parliament.