回複：Thank you all for the replies! more questions about WOM

first, not necessary to send more letter. Even there is requirement for "exhausted administrative remedy" for Writ of Mandamus (WOM), there is no clear definition of how much is "exhausted".

secondary, which Court you belong to will make big difference

third, not necessary to have lawyer if you have strong case, for those file lawsuit with lawyer, it is called "Pro Se".

for more information and similar cases for immigrantion related WOM, 詳細情況見這裏