My phone won't let me download any apps from app store and takes me to account settings when i click an app i want to download and says there was a problem with a previous purchase and tells me to update my payment method. what do i do

I have done that already. I have also tried using different cards to get it to work and nothing is working. It brings me right back to account settings and won't let me go any further. I have money in each account I was trying to use, so I know that's not the problem. The store associate said typically there should be a none button that you can choose but i don't have that option. I've never boughten anything off of the app store anyways so I don't know why its telling me this. I always get free apps. Anything else you would suggest trying?