I have 3 QR tickets pending refunding as early as the first week of March.

I contacted Amex for resolution in April. They reversed the charges within a few weeks of me contacting them, and by June 14th the reversal will be permanent if Qatar does not respond (which seems unlikely that they will). The Amex agent on the phone told me that they are getting a lot of complaints from Qatar and Copa customers. The agent told me that COPA has a sales office in Miami, where the phone is now no longer answered.

On the brighter side, UA took about 6 weeks to process my refund. I got refunds on 2 CX tickets back in March within about 3-4 weeks.

I have 2 more refunds pending with CX which their website says should process in about 7-10 days.

My worst experience is, by far, with QR.