FINN Senior Backend Engineer (Node Js) interview questions

I applied online at FINN's website for the position. I was promptly contacted and arranged a touch-base interview with the VP of engineering, who was really friendly and nice to talk to making the whole process very pleasant. Afterward, I got handed a take-home coding challenge with a week's deadline, which was appropriate for the given challenge. One thing that I didn't enjoy was that the challenge required a video submission of going through the code. The tool to record it, wasn't really user-friendly making the process a bit awkward and cumbersome. Up to here, everything was good, until I received a negative response regarding the coding challenge. My problem is not with the application rejection, but with the feedback that came with it. It mentioned that the deliverable was not runnable (was running properly), missing instructions (separate clear instruction file included), and some implementation-wise disagreements. I replied back to each point in the given feedback where it was wrong (no missing files etc), while also giving a solid explanation backing up my approach. However, I never heard back. This kind of communication really brought down the overall experience of what otherwise seemed to be quite a good company. I would have preferred a quick call (also instead of the video submission) where implementation is discussed to get a complete understanding of each side's thoughts. Nevertheless, not responding to an applicant is a red flag, especially when they have devoted their personal time to go through the challenge and all its requirements.