The easiest way to block a phone number to call, is to use the system functionality of the mobile phone. Most often, the lockout feature available on smartphones. For example, open address book and select the caller, the calls from which you want to limit. If you received calls from a number that is not among your contacts list, paste it there and name it, for example, "unwanted caller 1" (later you may have several similar rooms). In extension settings, look for and select "block" or "add to blacklist".
The option of blocking the phone number works in the following way: your smartphone will automatically reset, all calls from unwanted caller. The owner of the phone doesn't even recognize that he was trying to call, while the caller attempts in each round will be displayed the message "number is busy". It is worth noting that many devices allow the black list, enable and disable it in different situations in the General settings of the phone.
Often it also happens that the option blacklist, so to block the number so didn't call you some tricky ways. For example, make sure that your room has no active voice mail. Further, the options for the numbers to activate the option "send calls directly to Voicemail". When attempting to call the subscriber will see the same inscription that the number is busy. In addition, add the caller to the blacklist by using a special application that you can download in the AppStore, Play Market or any other system store depending on the device. Search for programs by keywords "black list" (blacklist), block (block).
The service "Black list" are available to connect almost all the major mobile operators. Most often it is paid and involves the imposition of blocking certain numbers, experts of the cellular company. Connect the option you can in any salon of communication through a personal account on the operator's website or by calling on free round-the-clock room support. Please note that calls from a number from another city or country and also from any suspiciously behaving subscriber can lock through the operator free. Usually employees of shops satisfy such a request on demand.