How can i start to complaining about someone...

We would like to inform you that you shall submit a complaint against them at the nearest police station, and they will be summoned, investigated, and legally punished, and they will sign a pledge not to do anything for you, since the actions they undertake are considered a crime that is legally punishable.
Article 351
Whoever threatens another person, in writing or verbally, to commit a crime against his life or his property, or against the life or property of another person, or to divulge matters which offend the latter's honor with instructions to commit or omit certain acts or with the intention to give such instructions, he shall be punished by imprisonment for a period not exceeding seven years.
Article 352
Whoever threatens another person to commit a crime against his life or property or against the life or property of another person, or to disclose matters which compromise his honor or modesty in cases other than those mentioned in the preceding Article, shall be punished by detention.
Article 353
Whoever threatens by words, deeds or signs, in writing or verbally, or indirectly through another person, in cases other than those mentioned in the two preceding Articles, shall be punished by detention for a period not exceeding one year or by a fine not exceeding ten thousand Dirhams.