BYD support so far has not impressed me favourably. Had an issue with my new car, took it to the workshop, they took apart some stuff and agreed that a part was faulty. However they need to submit a request to HQ for approval, which will take 2 weeks. And THEN they'll order the part, which will take ANOTHER 2 weeks. 1 month, just for a simple issue. It's a good thing my car is working, if this was a critical issue I'd be carless for a month due to their bureaucracy.
I suspect they've grown way too fast for their support infrastructure to keep up with.