If you decide to rid yourself of contact with any of the subscribers of the cellular network, check with your operator if he provides such services. If Yes, then subscribe to this service and make unnecessary room in the "black list". This option is programmed in your phone, simply find it in the corresponding settings section, enter the unwanted number and activate.
Some operators provide two modes: black and white lists. If your carrier also supports both modes, connecting them, try not to get confused, which one is active at one time or another.
Forbidden rooms will be taken by phone as undecided. In consequence, you will be able to choose that will not hear caller caller: a phrase stating that the subscriber is not available, the busy tone or redirect to Voicemail.
If the operator will not be able to help you, carefully read the user manual of your phone. Almost all modern phone models, the ability to create "black list" himself. Depending on the model, actions that are produced by the phone numbersof mi from this list, different. The phone can just turn off the sound when you call from unwanted numbers, can simply block the incoming call and even SMS.
Find in the menu the tab "phonebook" or similar (depending on the model of phone, tab can have different names), select the number you want to make the "black list" and select edit function.
Once you get to a menu where one of the action room will be asked to place it in the filter or "black list", confirm your decision. In most cases, unwanted phone numbers will receive a busy signal.
Don't forget that all settings will be in this phone and if you want to change the unit, all you will need to configure again.