Called my cell phone, left no message. Called back using *67, got fast busy initially. Called again and got same message as shark12. Listened for 5 or 6 repeats of their "Lisa" message then just set the phone aside to let it repeat itself to tie up their lines, if even a small fraction of a percent. Not sure how long it went on.
I don't have the $ to give my son a phone, and don't think he needs one... anyways, there are always thousands of phones sold for kids after a school shooting; after Sandy hook, there was record breaking sales on simple kids cell phones... lots of paranoid parents. And BTW, when I was 10 we could have really used a phone after football practice. We'd always call my mom from 1800 collect but a lot of times, she hadn't gotten home from work yet, and no one had cell phones back then, would have been nice if they did and if we did.
Block the calls. Ask her phone provider how. Or put the pest in her contacts list and assign it the ring tone "no ring". That will send the calls to voicemail. She'll have to clean out her voice mail occasionally.