Just to be clear, you are annoyed because DuckDuckGo offered to pay for your interview(!) but you didn’t like the payment processor they chose to reimburse you with?
Do you really want me to respond to this question?
I'll set aside a whole hour, but I think it'd be rude to list off all the reasons I'm annoyed I didn't get the role I applied for, or pointed at something a better fit for my CV.
The larger issue is I applied there after having my career obstructed for over a decade because I agree with the fouders. I've met several of their employees -- I told many people offline some of them were incredibly skilled in their roles.
That meta level pattern of being obstructed, trying to help others who have that same issue, then being thrust further into precarity really grinds my gears.
Feel free to ask another question like the above, and I'll reply in even more detail.