About App Store

Hello. I have a problem with my App Store. I am not allowed to install or update my apps and I don’t know why. I have brought my iPhone to iDeal and they told me that I am blocked on App Store because of payment problem in the past, but I had not installed any app that is not free. Unfortunately, they could not help me. I have been blocked since this autumn. Please fix this or tell me how can I solve it. Thank you.