in regards to ex. call on the fone all the time

my friend lives in south carolina and i am trying to help her,her ex. girlfriend is always caling sometimes good voicemails somevery threating and nasty like you can see other women but your not going anywhere they broke up a yr. ago and she just started doing this because my friend has moved on and meant someone i advised her to save all txts and voicemails she has and even sent them to me to read and hear what can she do i advised no more talking on the fone and not to respond back to voicemail or txts. the ex. is determined not leave the picture and calls the kids fone each day to try and get her to get on fone and talk i told her even though ex. is Godmother u may have to drop that because she will continue to use that as a way to stay around.please help thank you