Well done on challenging. I refer this back to the word 'fairness' on your original point. Nothing is fair. You're reliant on people (including yourself) and people are flawed.
You've done exactly the right thing. ***** footing around the issue does nothing but encourage further inaction and delay. Personally I'd go and see the RDO in person, but that's just me. But keep your written comms clear, to the point & polite. Always 'look forward to your response'.
Once you have you promotion application sorted then be very proactive yourself. If you have free days then write to leagues and tell them you're available, even in neighbouring counties.
No point waiting to see if things run 'fairly'. Go and make it happen.