Mercer Human Capital Analyst interview questions

This is for the Dubai office. August 2016: a friend working at Mercer Dubai sent in my resume to Talent Management and Information Solutions department October 2016: received LinkedIn invite from HR manager; later in the month: first interview with Principal of department - both agreed that it went very well. After some following up with HR... February 2017: HR manager told me that there will be a final round of interviews + excel exercise April 2017: second interview with consultant; decision makers asked him to test my thinking process; missed some key steps but consultant assured me that he would write a great review for me. Went well overall After some following up with HR... Rejected! I was disappointed because the interviews went well. Even more disheartened and irritated because as an HR consulting firm that provides their clients with best practices Mercer Dubai should have been more considerate with their expectations and correspondance with candidates. Hypocritical that they led me on when their goal is to improve employees' morale and attrition rates.