It wasn't required to call for a refund; if you had a refundable voucher, it should have been possible to request the refund online.

I had several of these and never needed to call to get any of them refunded. Some of them did, however, take months to be refunded.

To the OP: do you have an Air France/Flying Blue account? And did you have such an account at the time you originally made this booking?

when you log into the Air France website, and click on "My Bookings", you should see an option to view all vouchers issued to your account.

If you click on "View Vouchers", you should be presented with a list of all vouchers that were issued.

You will also see the expiry date, and the information regarding the use of the vouchers.

Here is the link to the FAQ.