Zingo 2.0 Hoverboard Unstable

My complaint is not really with Tevo but with a product of theirs, Zingo 2.0. We recently bought one for my 11yr old and he is really stable and balanced on the board. However we noticed it flung him off for no real reason at home on our tiles. We took him to ride it in an open smoothe area at Peoples park and with more space he went a bit faster and again it flung him off, but this time the board richosheted with him and broke his Tibia and fibula. We fully understand there are risks with all boards and kids in general but with this it seems it gets unstable at a certain speed which we feel if that's the case, should not reach those speeds. The safety on this product needs to be reevaluated and the speed throttled if it cannot safely go at the speed it says it does. Had he crashed into something or avoided something it would have been understandable but he was riding in an open area and the board itself being so solid and heavy broke his bones. This post is to bring awareness not slam a product or company as what we are going through with our son is the most awful thing. Please Tevo investigate this.