TrueCall Care
I have posted about TrueCall Care many times, but it seems appropriate to mention it again. I bought a unit for my mother's house. She used to be terrified of the phone ringing (the sound, not the intrusion). Her live-in carer might be sleeping during her much needed afternoon break and would be startled awake by a telepest.
The unit costs £100 VAT exempt from the Alzheimer's Society
http://shop.alzheimers.org.uk/category/telephones-and-call-blockers (similar prices from other retailers such as AgeUK).
You can configure your caller lists to have trusted callers who get straight through; message screening for other calls that requires the caller to enter a code - this cuts out most automatically dialled calls; and blocking specific numbers or international numbers. You can monitor usage online and tweak your trusted and 'zap' lists.
You can even set it up so that ONLY trusted callers are allowed through. You could then set the screening message to say something like "Thank you for calling. We are not taking calls on this number. If you need to contact Mary, please phone her daughter Susan." This would mean that any caller NOT on the trusted list would get the screening message and no option to be connected.
At my mum's house the pester calls continue but they NEVER get connected. I just monitor them online and add any numbers to the zap list that I can identify as sales or survey numbers.
I can't tell you what a difference it makes to our sense of privacy and well-being. Nuisance calls can put you in a bad mood for hours, and the anticipation of being pestered makes you growl at any unfamiliar caller!
At my mum's house I answer with a light and friendly tone of voice because I know that the call will not be unwelcome.
When I go home to my own house I dread the phone ringing because 2 out of 3 calls is unwelcome and a waste of my time. Why don't I get a machine for myself? OH thinks it is an unnecessary extravagance.
In 2016 I will start to get my employment pension, i.e. MY money! A TrueCall Care machine is on my shopping list.