An update on my side concerning the delayed refund. AF refunded my Amex more than 2 weeks after the cancellation of the tickets, and I had time to file a DOT claim in between. The thing is that due to currency exchange fluctuations between EUR/USD, I lost 40 Euros in the process. After receiving a standard apologetic message from AF mentioning my DOT case number, I replied to it stating I lost 40 euros in the process and was requesting a refund for this, also mentioning that since I was a frequent flyer with AF/KL, I would accept a travel voucher if the value is greater than 40 euros. I got the reply yesterday and they offered me a voucher of 150 Euros as a "settlement". So I guess the case is closed on my side, it could have been worse, but will keep flying oneworld long-haul for the time being, and instead will be going to Australia and Japan with QR with the amount I was supposed to spend on AF First.