NAGIOS notification command for service/contactgroup

It seems that you need to define your contacts twice. One definition to be notified only by email and another definition to be notified by both email and phone.

define contact{
        name                            generic-contact-high
        service_notification_period     24x7
        host_notification_period        24x7
        service_notification_options    w,u,c,r,f,s
        host_notification_options       d,u,r,f,s
        service_notification_commands   notify-service-by-email,notify-service-by-phone
        host_notification_commands      notify-host-by-email
        register                        0
        }

define contact{
        name                            generic-contact-med
        service_notification_period     24x7
        host_notification_period        24x7
        service_notification_options    w,u,c,r,f,s
        host_notification_options       d,u,r,f,s
        service_notification_commands   notify-service-by-email
        host_notification_commands      notify-host-by-email
        register                        0
        }

Your contacts should be defined according to these two types of contacts:

define contact{
    contact_name    sam-high
    use             generic-contact-high
    alias           Sam
    email           sam[...]
    address1        +44[...]
    }

define contact{
    contact_name    sam-med
    use             generic-contact-med
    alias           Sam
    email           sam[...]
    address1        +44[...]
    }