This problem has been dealt with in the most recent Which magazine.
Comments from readers included the suggestion that the TPS is completely 'toothless', something that I can confirm through personal experience. For one thing, UK companies can get around it be routing their calls through a foreign call centre and, for another, they can effectively disguise the location of their call centres by substituting virtually any number they want.
Certainly, although I am on the TPS list, I shall no longer bother with reporting unsolicited calls. There are many tactics available to us though, my favourite being to feign interest and keep them talking for as long as possible. This, presumably, costs them time and money and also reduces the time they can spend on making calls to other 'victims'. It may not ever stop such calls, but it does give me a sort of pleasure!
