I completely agree with your comments, it can be frustrating. However the fact that you got one straight away on the second try makes you wonder whether it might have been a coincidence that a seat opened up? You seem to indicate there was absolutely no hesitation from the agent's side to grant you the upgrade
True, but the first agent did state that no such quota for Golds ever existed (which is completely false). Perhaps he was new or had been misinformed, but I've learnt (in part to this forum!) that arguing is a waste of time and best to just call back hoping for another agent.
Regarding the Gold desk, I put in my skywards number, pin and each person who answered, answered by "Thank you for calling the Gold desk". Could be coincidence as I've never had that before.