I'm not sure what airlines you are dealing with but I'd call back and ask to talk to a supervisor. In August, my sister purchased tickets to Orlando from Pittsburgh and within a week the price had gone down about 40 dollars per tickt. She called and they didn't give her a refund but they did issue her vouchers for a future flight. This was US Airways.
That said, I also had a similar transaction recently. My husband and I had booked trips to Las Vegas for October. Because of the travails of the airlines, they cancelled and "rescheduled" our return flight for over 12 hours earlier. When I first called to complain, the women on the line told me that there was nothing she could do except fly me through Houston Texas to get back on a later flight. I told her that I did not wish to go through Texas to get back to PA. She then told me again that there was nothing she could do except if I wanted to change, I would have to pay the $100 change fee. By the way I forgot to mention I booked these in May. I asked to speak to her manager. I was very polite and explained to him that this was not an acceptable situation. He agreed to cancel my ressies and let me rebook at a later date without any change fee. He also said that I could use the "credit" of the purchased ticket against a similar fare flight to even a different destination. He then said that if the new fare was lower, I would get a refund of the difference. This was Continental Airlines.
I know this is a long reply but I just want to point out one thing. NEVER TAKE A "NO" ANSWER FROM SOMEONE WHO DIDN'T HAVE THE AUTHORITY TO TELL YOU "YES" TO BEGIN WITH. Call back and ask to talk to a supervisor.