Addicted to Ambien

My mother has been taking it to help her sleep since she was in her early 30s and she’s now in her 50s. She literally claim that she can’t fall asleep without it. And she takes more than the recommended does of 1 pill. She will take 2. I don’t know how to help her. She claims she’s tried melatonin, tart cherry juice and I guess other natural remedies. Taking that crap long term can’t be good. Her doctor stopped prescribing it and she resorting to getting other people to get it for her. She tried to use me but I said No and guess what she did? She called my doctors office and acted like me to get a prescription and they sent it over. I found out because when I went in for my checkup they asked if I was still taking it and I was like I don’t take that. I was LIVID. Any ideas on getting her help. I really don’t think she will go to rehab. I don’t know what’s causing her insomnia. Any advice would be appreciated