What is the Shar'i ruling on borrowing money from Iraqi banks to buy a house, with a penalty clause to pay additional fees if the repayment period exceeds twenty years?

What is called "additional charges" that the borrower is required to pay when late in repayment: if they are administrative fees for following up on the loan transaction and its collection, then there is no objection to them. However, if they are a percentage linked to the remaining loan amount or are not originally administrative fees, then they are forbidden usurious interest, which is not permissible to accept except out of a recognized necessity, and the assessment of necessity falls to the competent authorities. The ruling depends on the reality of these charges: are they service fees or usurious interest?