it has big hangingin and unable to open lcd and icant even get the calls and sometimes i cant open lcd and maybe it works after 3 or 4 times reseting

my iPhone 6 plus has too much hang and unable to open its face specially when I am going somewhere else from my home its face goes locked and I cant open it until reset the phone 3 or 4 times and sometimes when it is on I cant get any calls and after resetting I see there is a lot missed calls that I never heard the ringing of them . I tried restore it by iTunes but iTunes did not restore it I don't know because of its problem or anything else