The due date for fines that have been 'fixed' due to a renewal are confusing/misleading as they show the new due date rather than the due date for which the fine was created. As an aside, we could also display 'Renewal date' in place of 'Returned date' in this table for renewed items.
Also, if an item is renewed twice, the second due date is recorded (not the original, not the new due date). It's like it's fixed to the due date of the item when the first fine was paid. I'll try to come up with a test plan, although not exactly sure how since it involves a lot of time in between the actions