After spending many hours troubleshooting, searching and trying out some answers on StackOverFlow. I couldn't get this to work properly, I need to be able to select any number that a contact have, but I always get CNLabelPhoneNumberMain or in some cases CNLabelPhoneNumberMobile even when selecting home/work number. 
I'm facing this trouble since long time and I appreciate if someone can point my mistake:
Here is my code:
@IBAction func addSupporterContactTapped(_ sender: UIButton) {
     let contactPicker = CNContactPickerViewController()
     contactPicker.displayedPropertyKeys = [CNContactGivenNameKey, CNContactFamilyNameKey, CNContactPhoneNumbersKey]
     contactPicker.delegate = self
     self.present(contactPicker, animated: true, completion: nil)
}
And this is how selection is made:
func contactPicker(_ picker: CNContactPickerViewController, didSelect contactProperty: CNContactProperty) {
    let numbers = contactProperty.contact.phoneNumbers
    var phoneNumber: String?
            for contact in numbers {
        switch contact.label {
        case CNLabelHome:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelWork:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelOther:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberMain:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberiPhone:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberMobile:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberPager:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberHomeFax:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberWorkFax:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        case CNLabelPhoneNumberOtherFax:
            print("contact.label = \(contact.label ?? "")")
            phoneNumber = (contact.value ).stringValue
        default:
            break
        }
    }
But in anyway, as I mentioned above, I never get the correctly selected number.
If it can help, When any number is selected, I get this printed in the console:
contact.label = _$!<Home>!$_
contact.label = _$!<Mobile>!$_
contact.label = _$!<HomeFAX>!$_
Is there anyone can help please?
 
                        
When you select a phone number in
picker: didSelect contactProperty:you get aCNPhoneNumberback in thevalueofcontactProperty