Apigee interview questions

Initially got call from Apigee Recruiter for scheduling initial round of interview, within 2 days I got that scheduled. Interviewer asked about my overall experience and some random questions to start off. When I expressed my interest towards product development/back end development, then he said h will forward my queries to recruiter/HR. Later I directly got an email from recruiter asking me to develop Offline Assignment within 7 days. It was an online Auctioning/Bidding system, with services such as putting item on an auction, placing bids, multiple bids should also be allowed, show top 5 bidders of a particular item, notify bidders about new item in place. I worked on this assignment for 7 days and finished it, replied them back within 7 days. I was confident since my solution was good complete and good enough to hear from recruiter, but to my surprise I got mail saying "Unfortunately, we won’t be moving forward with your application at this time" after some 15-20 days of submission. It was bad bad approach, you asked someone to build a complete system, who works for 7 days and gives you proper solution which is tested, I believe at least he deserves a call to say something if you find solution is not proper. BAD interviewing process. I wasted my 7 days building a solution for them....