Coach interview questions

Did three interviews, on my last interview they asked about my previous manager, I told them I wasn't happy with him, and i wanted to leave my previous company, the manager said i got the job i would be called the following tuesday for orientation, (it was friday) called me monday, and said they decided to go with another candidate, and no longer wish to pursue with my application, AFTER TELLING ME I GOT THE JOB! Terrible, no professionalism. I wasted 3 weeks. I applied one week, did my interview in 2 weeks and all 3 interviews took 2 weeks to complete, WASTED TIME!