I had a friend like that, would call once or twice a year, usually when she wanted me to forge something for her. Not only that, she'd call at night knowing thats when I worked, would leave a message "I can't remember your hours", it was a toll call so I'd have to call her back. This went on longer than it should have, over five years. The last time she called, I had to called her back, told her I wouldn't do the form for her any more so she could get low cost medical, and brought up about only calling when needing something, especially at night when she had to know by now thats when I worked. "Please do it one more time, don't know what I'll do if you don't"..."not my problem", and hung up, never heard from her again, and didn't want to.