Does the phone call give the name of the company or the name of their service??
If you can get a name or a service, should be easy to track them down.
Do a search for the company name on google. If google gives the domain name (i.e. the URL) for the company, then do a search for the domain name (for example use nswhois.domainregistry.com). This is a good place to find all the contact details for the company.

Then take it a step further and search for the company name on the companies registration office. Some agencies will be a 'child' company of a holding company. You should be able to track down the directors of the holding company this way.

You can use that information to chase them up, plus you could also treat them to a bit of their own medicine and use their number and contact details to play them at their game. I'll leave that up to your imagination. :D
(sarcasmo needs more sleep, Tue 8 Sep 2009, 13:11, 1 reply)

Nameless
No, they don't - that's part of the problem. Every time she tries to get the name of the company, or any information at all, the guy hangs up.
(calamarain just invented dehydrated water, Tue 8 Sep 2009, 17:07, closed)

baxtards..
I don't suppose you could use an answering machine, with a blank outgoing message, and tell your mother to leave the answerphone to handle the call when an unlisted number appears.
If it's someone that needs to get through to your mother, she'll hear the voicemail (if you can get an answerphone with a speaker) and she can determine whether to ignore the call or pick up the handset and take the call.
This way you can gather evidence, for a nuisance complaint, when the phone pest does call and you can use it as grounds for a nuisance complaint to the police.

** [edit] as minimalist was saying.. I probably replied to the wrong part of the thread **
(sarcasmo needs more sleep, Wed 9 Sep 2009, 16:33, closed)