buttons located above the band.

[Step_ik1]

[Uliwooly]

I see it, take it to a Sony repair center ASAP 

[Alexander1]

Thanks for the video. Obviously you have some issues with the touch screen. I suggest that you have your phone examined by an authorized service center, lease contact your local support team for more information about the your service center: 

http://www.sonymobile.com/global-en/support/contact-us/