I did the same with my RBC Starbucks Duetto Card.
It was also 19.5%, and the interest was piling up.
I, however, had absolutely no difficulty changing my card to the Classic with Low Rate option, which is 11.5%.
All I had to do was call the credit department and ask, and thats it.
I got a very polite person who told me it was possible, because my account was in excellent standing (R1) with absolutely no late payments. It did, however, put a hit on my TransUnion file (but who cares anyway, most banks turn to Equifax), but it sure was worth it and the mere $20.00 annual fee
To this day, I've saved a LOT of money.
My personal banker at CIBC told me that RBC really focuses on their credit cards, but for anything else its almost impossible to get. I have an account at RBC, which I don't even use, and my application for overdraft protection was declined, however I was able to raise my VISA limit from $3500 to $6000. When this increase happened, I paid off my Source card with my visa.
I just got approved for a sears card today, and I plan to buy a $720 train ticket on it, and then pay it off immediately, thus getting all those sears points and paying no interest.