Celebrity Cruises – Has anyone successfully upgraded after a price drop?

I’m looking for some advice from experienced Celebrity cruisers.
I currently have a reservation in an Infinite Veranda cabin, and I noticed that AquaClass is now cheaper than the Infinite Veranda fare I originally booked.

So far, I have only paid the $330 deposit, and I would like to move my existing reservation to AquaClass, ideally keeping the same booking and simply paying any difference that may be due, rather than cancelling and making a completely new reservation.

I booked directly through the Celebrity Cruises website because I live in a small country where there are no Celebrity representatives or travel agents specializing in Celebrity Cruises. The difficulty is that I’m outside the US, and I haven’t had much luck getting a clear answer through Celebrity’s online chat. For those who have been in a similar situation: * *

Have you ever successfully changed an existing reservation to a higher category after the price dropped? If AquaClass is now cheaper than your original Infinite Veranda booking, were you able to have the fare adjusted? * *
Who did you contact ? Celebrity directly, a particular department, or a travel agent?

If you are outside the US, was there a particular way of contacting Celebrity that worked better?

Were you able to keep the original booking and apply the $330 deposit to the new cabin or fare? I’d particularly love to hear from anyone who has managed to do this with AquaClass, rather than through the MoveUp program.

Any advice or personal experiences would be greatly appreciated!