im pretty sure all lexus would of done was to empty any old gearbox fluid out,change the filter and add new fluid tbh so £400 for that service sounds a lot anyway,,sorry this has happened rajesh - i imagine lexus will offer to take the money youve spent with them off the price of a refurb,,,, in all honesty as said earlier i doubt theyll refurb it in house so it would probably go off to a local specialist like the ones that quoted you £1300 ish ,,, if you went down that route at least you might keep the loan lexus while its being done and also have the piece of mind of a lexus warranty on work carried out - either way its not gonna be a cheap fix,sorry mate