The others are right, plus...he needs to actually go and try to pick her up, and have a refusal documented with a police report. Have him go to a nearby store, buy something, and save the receipt to show he was in the area at the appointed time. Just hearing on the phone that she's not coming will not cut it. Mom could say he just didn't bother to show up. And save DD's phone message.
Also there is a
form letter on here that you can fill in and send to mom (registered) that states that, as per the
court order (and quote the relevant paragraphs), you will be exercising your parenting time on X day, at X time, and to have DD available or you may have to pursue legal action. Or maybe you could email Mom and say, is this what dd really wants? and get her to say that dd will not be coming any more. You may or may not be able to use that in court.
Many kids who say (in the CP's presence) they don't want to spend time with the other parent, once they are with the ncp, they are their usual happy selves. Obviously Mom has planted this junk in dd's head and dd is just going along with Mom. Kids do what they have to do.