If you go by one of the stores again, you might ask them if there's a China Mobile corporate account on WeChat that they can contact. Things increasingly get done via WeChat here these days, while voicemail and email inboxes are sometimes left unattended. Also, WeChat's format makes it more difficult to give someone the runaround.
Grace is staffed by American doctors and, in my experience, provides the same level of expertise and standard of care that you would expect to find in a good clinic in the U.S. I highly recommend them.