I'm unsure if this is something that changed or not. I am in debt with Duke (both directly from the loan and in upkeep) for a very long time now. When I visit the loan shark he gives me the line "Had enough yet? I can keep this up so long as yous got blood in your bones. Pay what you owe." despite the fact he hasn't actually done anything. Sorry if this is a change I missed.
Edit: I have not made any fee repayments in the last 10 months, which from looking it up on the wiki means I should be getting Duke events