Some time ago I had a reservation ticketed on a non ref. fare;
I changed it a few days later and I was charged for the change fee and for the fare increase;
Later I changed it again and I was charged for the change fee and the fare went down to lower than the original fare;
I was told by the agent that I would have received a certificate for the difference. This is consistent with my previous experiences.
I have received the certificate but it shows a total value of $0.00;
Does anybody know if this is a mistake or the rules changed?