Is there a way for revenge?

i babysat for this woman for a week. we clearly agreed that it would be $40 / day for 2 kids. she sent her daughter to give me $100 dollars one night and said that she'd give me another $100 the next day. i patiently waited, but she never came back. i called a couple of times, but she wont answer b/c she knows my # and doesnt answer private calls when i hide my #. i left a couple of messages too. i also used my husband's cell to call and she answered but hung up when i spoke. i know where her kids go to school. any advice? serious answers only... and no, i will not kidnap her kids.