I would download the 10.1 public beta first and see if this improves things. As lost of us have stated the beta is miles better. This is a software fault so exchanging your phone won't do anything so unless you are giving up on the iPhone 7 there is not much point.Haven't decided what to do yet tbh
There is the slight possibility that your iPhone is faulty and it isn't related to the software problem but until you try the beta you won't know.