Hi @lucianstan1900, welcome to our forum! I can check if your file has the right iban now but if it's wrong I'm afraid I can't change it through here. From what you're describing we'll still have the wrong iban on file.
I'd recommend you to give us a call on 0800-0402 (toll free) or chat with us on www.kpn.com/service (click a product, select “ik heb een andere vraag en wil graag contact”, scroll down to the chat button)