scammed maybe a strong word david but the basic rule is, your the marketing manager of your company so its up to you to spend your advertising budget wisely, if some one calls you to advertise in there magazine you firstly ask for a copy to be sent to you. if they can't then don't, you then ask where these publication are distributed, once you know, go check, if there not there then don't. maybe ask who there printers are and contact them on real amounts printed (not sure if they would give you that info though) but basically do your homework before advertising in any cold callers avenues.
ps.... even if you have heard of them, it might be worth checking they are for real, i get 10 google and orange companies a week ringing me, and yet i know none of them are really google and orange, they just make it sound like they are.
pps I've only ever been had once and they were genuine, yellow pages, total waste of money for me personally, all though, ive just had a £200 job from a free listing so i'm slowly clawing it back
pps. my rule is simple, if someone calls, they either want there carpets cleaned of they can do one. simples. all though i do entertain my self with them when i'm bored, which is mean but hey!! they called me right?