FareHarbor interview questions

In the beginning the process was very efficient. I had a first screening phone call, and in couple of days they already scheduled a second face to face interview. The next day already i received an email with the assignment. The was no time frame. I finalized the assignment in couple of days, send it in. Afterwards I did not receive any confirmation email, I tried to follow up if my assignment was received, I got no answer. Send another email, when shall i expect the answer. Still no response. The next week I tried calling but the is no phone number provided of the office in Amsterdam so I got in touch with customer service who ensured me that the recruiter will call me back. Unfortunately there was no answer again. In couple days I received very general email that i was not selected for the job. I replied very politely, thanking for their email and said that I respect their decision. The only thing I asked was to receive a feedback why I was not selected for the job. No answer. The next day I sent a new email asking to provide a phone number so maybe it is easier and less time consuming to give feedback, but again, I had no answer. I find it very disappointing because it also took me time and effort to apply for the job and attend interviews and the only thing i asked at the end was some feedback, but apparently it is too much to ask.