To add subscribers in the black list for "IPhone" in several ways. The easiest way to do this is through the contacts list. Go to the address book of your phone and select the unwanted contact. If the number you want to block is not there, add it and specify any appropriate name. Browse about the man down and select "Block caller". Now if people try to call your number, the call is always to fold.
The second way to place the caller in the black list on an iPhone is to install special apps from the AppStore. Use the search this service to find the program iBlackList. As soon as it is installed in the program menu will be added to all the existing phone contacts list. Select from them and add it to the blacklist. Likewise works and app MCleaner.
Contact the helpdesk of your mobile operator to ask him about the possibility of connecting the special service "Black list". This feature is available in almost all operators. Over a certain amount you get access to the advanced settings of the list of your contacts and can add contacts to the blacklist on the "IPhone". You can also activate the service on the operator's website or contact your nearest office for customer service.