Well, Mel, Alan just did a little blunder by calling that number, he confirmed your phone number and address for selling as part of a third-party "verified" consumer list (unless he called from a payphone).
The best thing to get off mailing lists is to contact virtually all of your creditors, catalogs, magazines, medical providers, pharmacies, grocers with whom you have any kind of rewards card, utilities, ISP, cable/satellite provider, and any website vendors and put a total restriction on ALL sharing of your info.
One of the latest tricks is to allow the company and "its subsidiaries" to send you "offers of interest". Once the "subsidiary" has your address/phone, then you have to start from scratch after the deed is done. You have to be quite distinct in your language and include a "total and complete
whole household opt-out of all marketing correspondence, postal, electronic, and phone".
Many of my friends have even seen offers sent to their pets and children. It's a machine running on premium.