App store Saying that my Payment wasnt completed

Trying to download a few needed apps on my device...I'm new to iPhone, so please bare with me.

The apps are free, I have already successfully downloaded other apps, but I seem to be having an issue all of a sudden, and it says "Payment Not Completed" every time a try to down load the app, which is free. I have a payment method set up, i dont think that is the issue.

What can I do?