[WindowsCentral.com]

Here's how you can easily and quickly block numbers in Windows 10 Mobile and Windows Phone 8.
There will be a time in life when you need to block someone, be it a telemarketer or someone who may be harassing you. Luckily, we've got a guide for owners of handsets running Windows Phone 8 and Windows 10 Mobile, which will allow for the blocking of numbers to prevent further frustration.

Full story from the WindowsCentral blog...

[G4Grandad]

Or we can simply wait a while until Microsoft's strategy turns all our phones into paperweights?

[ElvinSloth986]

How to block calls on Windows phones with this guide.
1.Navigate to Settings.
2.Choose Call+SMS Filter.
3.Accept the terms of use and privacy policy.
4.Turn on the toggle to block numbers.
5.Go to your call history by tapping the Phone app.
6.Long press the number you want to block.
7.Choose Block Number.
8.SelectOk.