ON April 17, Hong Kong lost the following - a thorough all-round coverage of world news; current events programmes which report on historical events as important as the South African elections; programmes which will report on health issues such as the risk of standard vaccination for pre-school children; an excellent series on Pan-African history and intelligent and intelligible weather forecasts with graphics which do not insult the viewer. We have also lost informative programmes such as Food and Drink, The Clothes Show and Film '94, valuable ''windows on the world'' for young Hong Kong professionals working in the burgeoning service industries and an excellent resource for students of English. ''And this is where we say goodbye to our viewers in Hong Kong.'' The BBC's World Service Television has been taken off STAR by the most cynical manipulator of news and Hong Kong, the most international city in Asia, is now worse off than the most isolated small town in India. ERICA LAINE New Territories WHEN I contracted to receive STAR TV, it was on the understanding that I would receive five channels of television. One has now been cancelled. Will STAR TV confirm that my next bill will be lower by 20 per cent? DAVID EDDY Kowloon