If you get cold calls after being with TPS for more than a month you should pass all details to them (TPS) for action as they request. They ask for a month to get the lists circulated.
If the company is not registered with TPS they can do little but if it is then there is a specific code agreed between them that should operate and enables TPS to apply penalties.
I registered some time back and have reduced cold calls to near zero; I am also ex-directory which helps with other companies not signed up with TPS.
What I really need now is a way of preventing those sellers of double glazing, electricity, gas, etc. that insist on knocking on my door at inconvenient times - like now!!!!