J.P. Morgan Senior Developer interview questions

I was called for the interview on Saturday May 17th 2014. There was a huge line of people waiting for clearing the security checks. It took almost an hour for me to get the clearance after all the hic ups i went into interview room. It was directly one on one discussion with the technical panel. Panel started interviewing me with basic java question to advanced concepts. It was very challenging to clear this round. Later i was said i might have to join with in a month for which i agreed provided they issue me a offer with in a month. I was called again for another round of interview on May 19th 2014 where the same panel asked me some more java questions. On the same day I was said i have cleared all the technical rounds and will be receiving a offer letter soon. Its been more than a month now and am still waiting to receive my offer letter. HR keeps telling me they don't have an update from higher management. I really don't understand how can a HR answer so unreasonably. They are very unprofessional in there response and time lines. My salary discussion happened after 25 days of telling me that i have cleared the technical rounds. How long do you expect a candidate to wait for you ? How long does it take to process a candidature ? If you are not interested in providing a job why do you give false hope to candidates ? Its actually a case of of IPC 420 cheating and false hope which i can file in court ? When they said i have been selected i stopped taking calls from other consultancy and gave a stop for my job hunt. Truly frustrating experience and unreasonable responses received from JPMC. Guys if you are reading this and going to attend an interview with this company, Give it a thought if they can play so hopelessly with a guy outside company what would be your position when you join them. Attend the interview for experience but do not join them i tell you they screw up your future plans just by the name of interview. Being a multi billion $ company you should learn how to handle a candidature in the first place.