Ok your in Canada - so am I. Here's the deal as I see it. You should have received every cent you paid in a refund. Depending on who you had your insurance with, your TA should have refunded that as well. The $480 should have been a "sorry" certificate which sometimes they give and sometimes they don't. Once you have it, they should honour it.
Now, I am a TA in Canada and it pains me to say this, but I question your TA. When you paid your deposit did it go straight to RCL or did it go through your TA's business credit card? Did you pay by cash or credit card?
Do you still have your original booking number? Call resolutions and question your refund and tell them you want to know why they are not honouring the certificate. Quite frankly, as I said, something is really wrong here.
However, first question - did you get a refund of every cent you paid for your deposit?