Apple Store billing

Just came back from 22 months in United States and I had to configured my iPhone in American to download my bank app. Since Wednesday I'm back in France, I change the configuration back. My phone is French. Impossible to download anything cause I have to fill something about my billing infos which I tried but the phone doesn't accept any kind of my payment because he is still "united state" configured. So I tried to change it as it says on apple website but this thing can't be change either because I have to add new billing infos first?? Like what ?? So it's a circle I can't do anything