I canceled an itinerary (within 24 hours of ticketing) with a $75 e-cert involved once. Here is my experience.

.bomb has some issues with cookies. I use linux system at work and use mozilla. I opened two windows simultaneously when I purchased the ticket. One window shows available itinerary and the other shows availablility of immediate CR1 confirmation. Before I hit the purchase button, I made sure that I got all the seats I wanted and the itinerary that I prefer. Then after I hit the purchase button, it shows a different itinerary. I called CSR to complain and they refer me to web support. I explained the problem to the web support and gave him my itinerary number, the web support emailed me another $75 e-cert.