Worship and the protection of other people's property are both religious responsibilities. One beneficial act does not automatically erase an unpaid obligation. The report singles out debt so that the creditor's claim is not treated as trivial.
Example: A person wishes to support a charitable project while also owing money that is due. The existing financial obligation needs serious attention. Detailed legal rulings about particular circumstances are a separate subject.
إِلَّا الدَّيْنَ is an exception construction. The word إِلَّا directs attention to the specific right excluded from the general expression.