EY Associate Consultant interview questions

The process consisted of 4 rounds. First, there was a GD Then there was a PI with a manager from the firm. It was more of a testing round. I was asked a case and a guesstimate. Third and the most important round was the PI with a partner from the firm. This one was more of an HR round where my work experience, confidence, communication skills etc. were being tested. The last round was just an HR round

I had a very bad experience with the EY. I was called for discussion regarding openings in Risk Assurance(ITRA) team. I had my both tech as well as HR interview on the same day and was given assurance of my selection by both of them. I also had my salary discussion with HR and even the goal setting for the year was also done with the manager. I was informed that i would be receiving my offer letter in next 2-3 weeks. I even received the mail asking for my salary details stating that "as a part of hiring process, we would like to move ahead with your candidature. please provide us the following docs.....blah..blah....blah..." As i was very confident of my selection, i resigned from my current company. I have already been released from my current company a month ago and i am currently without any job. It has been more than 2 months now and i have still not received my offer letter from EY. I have tried to reach HR several times over phone & mail but all in vain. They are not answering to my calls & mails.