Guys if you have been receiving a lot of phone calls that are either silent or offering a) Claims Management for an accident that you never had (and they don't know your name!) b) Offering to make a PPI claim for PPI that you never took out or C) Offering to sort out credit card debit, then these may well be the guys calling you.
They have a whole list of phone numbers both land line and mobile that they use and mostly they indicate "Number Witheld " when they call. Well last week they cold called me and I pressed the option 5 when their automated phone system called my mobile and I have just had a call back from a humanoid asking about an insurance claim in the last 3 years that I (never) made as I have not had an accident in the last 30 years let alone 3 years. The caller's number was left on my mobile so I Googled it and they appear to be a bunch of cowboys posing as a legal IFA. One of the hits that came up in google was to a phone pest website Telepest and there they list all the numbers known to be used by Stevenson Drake
http://www.telepest.co.uk/Stevenson+Drake so if you want to block these numbers on your smartphone or BT8500 then surf over to telepest and and list them as contacts, then block them! Stevenson Drake are based in Cheshire and have a website
http://www.stevensondrake.com
FYI the number that called me was 07893 072142 - please feel free to call it and annoy them!