Hi Surviving
Sounds like you have done the right thing by stopping contact if your daughter is telling you that she is being bullied and hurt during contact with your ex. Keep a diary of anything your daughter tells you about how she feels about contact and any changes in behaviour if there is talk of further contact. You might want to encourage her to talk to a teacher at school as the more professionals she discloses this kind of information to the better the evidence against him is.
Take care and keep posting
Lisa