Billing issue with declined card on iPhone

So my card got declined. i owed 43 dollars. i didn’t have enough. now. i have 57 bucks! but its not charging to my card like it has before. i cant add or change my payment as i only have one card. will it eventually charge? i cant download apps or anything. i also did not even buy those things as a child who had my phone did. so when i get charged i will get a refund but i have not got charged yet.

[Re-Titled by Moderator]