With respect, monkey (young man) is "manki".
In pidgin english those words, singly, or as a phrase and spelt like that, don't exist. If you talk about a person's place the phrase would be, ples bilong mi Goroka or Kabwum whatever.
The slogan :'mangi lo peles' could be "tok ples" or the person's local language. It might even mean what you say in tok ples but it isn't pidgin.
Lukim yu.