Arbeidsgiver tror ikke på varsler

I am a female employee. I have reported incidents of collective bullying, and sexual harassment at my workplace. My employer interviewed me twice and interviewed the accused but reached the conclusion that there is no substance to my accusations. He informed me that some of the accused are considering going to court for defamation. I am in real shock. I do not know how to act under these circumstances. I am a foreigner and I do not know how laws and courts act in NORWAY.