THE Legal Department has filed an application to the High Court to strike out a writ seeking compensation from the Governor, Chris Patten, for alleged broken promises which led to a businessman losing a bet. A department spokesman called the three-page writ ''scandalous, frivolous and vexatious'', adding that it was an abuse of the process of court. The summons also failed to disclose reasonable claims of action, he said. The spokesman did not elaborate, saying that the case would be argued before Mr Justice Barnett on Monday. Kwun Tong resident Philip Lam Yung-tak claims he bet that a counter-proposal he submitted on the electoral reforms would be included in the compendium of public responses on the package, having in mind Mr Patten's ''friendly invitation and announcement that the proposals will be published''. But he found out that he had been ''misled by the announcements and introduction of the first defendant'' when the compendium was published in January 1993.