tough luck. i’m sorry this happened to you. it’s not uncommon when you deal with china. in furniture this stuff happens all the time. sometimes when my company goes outside it’s own chinese factories, we use the DOD or nasa approach and split up components to different places so they can’t tell what the hell they’re making.
i suspect the 1 year push on the prototype left your chinese partner very agitated. this stuff happens so much, it’s not even funny anymore. even with chinese patents in place, it’s no protection. it’s difficult to control the information of product development over there unless you have people in place who can watch_over_everything. even then, there is still a chance of a major infringement.
live and learn. move on.