I am fed up with cold callers. I am fed up with people telephoning, trying to find out about my missold PPI, or when I am going to get my insulation sorted. This happens on a daily basis: it seems to be the only time my landline rings and, yes, I am registered with the telephone preference service. I am particularly fed up with my wretched credit card provider ringing me, then saying they will not go any further until I answer their security questions, but will not answer mine to verify who they are. Short of changing my 'phone number and not answering the door, how do I get rid of them all?