As former Credit Card(CC) CSR for Citi, I can assure you that you can still open a dispute even though more than a year has passed. You will only be compensated for the ticket that you couldn't use, they can't reimburse you for items purchased from companies that are not directly involved with the dispute. When you call make sure you have the following:

1. Name of the disputed company
2. Approx. date of the purchase, and date of the canceled flight
3. Dates of your attempts at solving the dispute with the company, if you have them.
4. Amount that you are disputing. Again, this can only be the amount you paid for your ticket, and not an amount that includes added cost of a hotel, taxi, meals, etc. It wouldn't make much sense for the CC co to charge back the hotel for something that wasn't their fault.

Set aside at least 25 minutes for this process. From your story, I think you have a really good chance at recovering your money. Best of luck!