Welcome to the forum and I hope we can help you. If I were you I would contact the Admin on kijiji, there must be a way to do that and ask them about the problem. Then place a new ad. I have to tell you that I really screen people who respond to my kijiji ad. The people who contact me from my ad on this site have done the work to try to find quality caregivers where the people who find you on kijiji sometimes are not always looking for quality and sometimes their first question is about your rates.
You learn as you interview people how to spot what we call the 'red flags' that will cause you problems as you try to work with parents. Ask us anything and we will try to help.