This could be made easier if your phone has a caller ID display. Even if the phone number is unknown, this will be displayed on the screen of your telephone. This will tell you that this is a prank or pointless call and you can take confidence in declining the call.
You could get in touch with your network provider and see if they can offer any assistance. They can help you block telephone numbers up to a certain limit. Nevertheless, this is problematic with blocked phone calls because you do not have a phone number that they can block for you.
For people who own smartphones, there are a number of applications that could come to rescue when unblocking blocked phone numbers. Install the application onto your phone and see if it can work its magic. Some applications even claim to be able to blacklist and record incoming calls.
If all else fails, you may be forced to change your phone number if you want the calls to stop. It is by no means ideal, but if the caller’s number remains unknown then you have no phone number to block out from calling you.
These calls, especially if they are coming from telemarketing and other such origins, often arise as a result of your personal details not being protected correctly. In future, try and be careful and selective with where you dispense your phone number. Although personal details should be protected by law, these details can sometimes get into the wrong hands.