Originally Posted by
notquiteaff
Potentially a different scenario, though. As danville 1K points out, if the CR1 cleared (even just for part of the entire trip) prior to the e500 window, then it should not be possible later to switch it to e500s. The CR1s have the advantage of clearing right away with availability.
This is the crux of the issue - and correctly stated.
If any portion cleared before your window, you should
not be entitled to substitute your method of payment.
That's the risk you take.