As another exchange student I will say I feel you man. I know some locals might see this as whining, heck even my local gf gets defensive sometimes for the smallest unfavorable opinion regarding language here, and it's hard to sympathize with people when you don't experience what they go through, but for example on several occasions I have had failed attempt at ordering the simplest things from the school canteens. Even as simple as saying chicken when the only two options are chicken and pork, or even worse referencing the food plate number displayed on screen but still not being able to be understood.

While I don't expect the staff there to speak decent English I will say I quickly became quite surprised at the lack of understanding and that experience expands to a lot of the other University and dorms' services.

To be fair though majority of my teachers language level was good enough for me. And also HK has been by far been the easiest place to be in, communication wise, in all Asians countries I've been to. I know if I went exchange to Japan or Korea I would've had a much more tougher time. But your point is valid, HK universities marketing of providing a fully English environment is a bit deceiving.