Wont update

This sucks. Everything in the app works perfectly fine (though I dont like the fact that it wont let us change our username -_-) but it isnt in the app that isnt working. Whenever I try to update Snapchat it never lets me and its stuck on the downloading part. And no—this isnt my phones fault. My wifi is connected and I have internet access. So WHY the hell is it not letting me update the app?!

Misschuchay about Snapchat, v10.14.1.0