Screen not working properly

Start here:--> If the screen isn’t working on your iPhone or iPad - Apple Support

If the issue persists, contact Apple Support directly, using this link:--> Get Support , or make an appointment and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector

After checking it out, they'll give you all the available options.

Regards

Giulio