Why does my iPhone keep redirecting to the App Store?

No matter what I do, I keep getting redirected to the App Store every single time. I update the app, I reinstall it, it never matters because instead of opening the app like a phone SHOULD, it keeps redirecting me to the App Store, and it won't open the file that is SENT TO ME. I CAN'T open anything that is sent to me. People send me videos, and I can't open them because the technology is. Please make an update or something where your phone STOPS redirecting you to the App Store, EVEN THOUGH THE APP IS FULLY UPDATED. I'm so tired of going through this every day. Now I have to open my messages from my COMPUTER and COPY links that are sent to me. It won't even let me use Safari and watch the video on the browser. PLEASE fix this!!!

[Edited by Moderator]