Solution for no ringing incoming calls from a certain number:

1. Change your “Call Alert” to group that you want to answer… eg: VIP, family, friend, business … etc.
2. Place the unwanted persons to a group & deselect this group in your “Call Alert” (for nokia: Settings->Tone Settings->Alert For …)
3. If your is an older model, allocate his number to group & then allocate the group with a blank … empty ringtone…

now, your mobile ring without ringtone (for unwanted people)

Download empy / blank ringtone: [Download]