Bloomberg Global Customer Support Representative interview questions

I am looking for a new job and I initially applied for the position through their website. It claimed that the position could be applied using my LinkedIn profile, but the fact is you have to complete a whole form through their system and you can also optionally submit your portfolio/cover letter. Ended up taking me longer than what I've expected for the application. I thought I would have to wait longer before getting any reply, but they have scheduled for a phone interview on the next day after my application. They actually arranged the interview 30 minutes earlier than my actual available slot, which I've decided to accept as I've suggested my lunch hours. I have got invited to the office for a second interview despite performing rather poorly out of nervousness, but ultimately I still failed to pass the 2nd interview (with 2 team leaders from the department) so that's the end of my story. Originally I should be seeing their APAC manager after job shadowing on the same day, but the manager wasn't available. Everyone seem to be very busy with their work, and people actually walked fast even within the office - so you can actually see how high efficiency will be expected. Fast-paced environment, and many tasks would have to be performed at the same time. People were friendly and they seem passionate with their job. Still a nice experience to visit their office.

The process took about 3 weeks. The questions are pretty much alike other people described. I ended up being interviewed by 4 different people. First, I shadowed someone for around 30 minutes. Then, there was an interview with two people and after, a 1 on 1 interview. I have no idea what did I do wrong, I really thought I went well because they said I went well after the interview, and my hopes were really high. The next day I received an automatic e-mail stating I was not selected for the position, without any piece of feedback. Thus, it is really hard to give advice.