@tkelly442: Please try heading to the Samsung Members app > Press and hold on the app icon > Diagnostics > Touch screen, and swipe your finger across the on-screen squares so they highlight. If you are unable to highlight the squares in the top half of the screen, then this suggests that there is a hardware issue that will need to be repaired by an authorised Samsung engineer. In this instance, please head to samsung.com > Scroll to the bottom of the page > Contact us, and get in touch via your preferred channel, and an advisor will be able to make the necessary arrangements for you.
Please be aware that any physical damage identified during the inspection will need to be repaired to ensure that it is not a contributing factor, and to bring the phone back to its warranty specifications. If your screen is cracked then this will result in the repair being chargeable, however please be assured that any costs will be communicated to you prior to the service going ahead.