I took my Seiko watch to be serviced today and found a sign at their (former) TST location indicating that they've relocated to some place in San Po Kong, accessible by a green minibus from Wong Tai Sin MTR station.
A while back, I couldn't get a new router to work and had to visit a service centre that took me an hour to find in Lai Chi Kok.
So I have this morsel of wisdom to offer: find out where a company's service centre is located before making a purchase!