Hi Francine,
I think what has happened is that you were probably watching the banks exchange rate, but the FX company's rate will be between 1 and 1.25 cents different and this is how they make their money. If your buy triggered yesterday it was because the rate was around 1.54 and dropping. I was watching it closely for the same reason.
The verbal agreement you made is legally binding. If you really wanted out, you could sell the dollars back to them, but you will be out of pocket.
It is so hard knowing when to transfer your money. We traded half of our large sum of money earlier in the week and decided at the last minute not to trade the other half for a while. It's a bit of a risk as the rate might go even lower as is the trend now, then we will have lost out. We don't need the other half for a couple of months, so we are hoping it might go in our favour again, but who knows. If it does drop again, you'll be pleased it triggered.
1.53 is not too bad as the rate did go as low as 1.47 a few months back, but I know we all want the most we can get, as we only do this exchange once and it can make a big difference.
For me, I spend most of my time tracking the exchange rate which I find stressful and part of me feels that once it's done, I can just forget about it.
Best of luck.