Pfizer Manager Position interview questions

Interview for Pfizer Greece. I have been given a case to prepare for the interview which took more than 25 hours of personal work. The meeting with the directors was very nice and the hiring manager indicated that he would like to collaborate with me. After 2 weeks received an automatic email that my application was declined and there is no feedback after I have reached to both parties. I have learned from other candidates that the salary they provide was not in my personal range. When you give a case to a candidate for an interview that takes pretty much time have the decent approach to provide feedback at least and not ghost.