unresponsive touchscreen

I am really disappointed(again) with the screen always freeze, freeze, and freeze again.... after the last time i experience this kind of problem back then in ios 9.1, again, i experience this problem again in 9.2.1, why you always disappoint me, Apple? Can't you just make your operating system as stable and powerfull as before? if not, i will just buy another android tablet since they are more flexible, easier to use, cheaper, and of course, at least have the non-freezing touch screen, and if i found that certain version of operating system trouble me, i can always downgrade to other version. In this case, how? you dont even allow me to downgrade operating system right? i always have all the trouble since i upgrade to ios 9.x.x, i really regret to uprade ios 9.x.x and also buy this pricy 64GB iPad Air 2, which cost me a lot and disappoint me so much.... so, how?