Hi there,
It sounds like you have been having a difficult time with this person posting your details on facebook.
No one has the right to make your phone number public without your permission and its important that you tell someone what’s happening. Most social networking sites will have help centres were they will tell you what to do if someone is using your information falsely.
Perhaps you could discuss it with a parent or an adult that you trust and get them to help you in reporting this to facebook.
You can also get more information about staying safe online at www.thinkyouknow.co.uk
Take care
Sam