UST Senior Business Analyst interview questions

My profile was referred to UST by one of my friend. Initially had an hr call to collect basic info and to schedule for 1st round of interview. The interview was scheduled for next day itself and was done promptly on time. It was followed by a manager round and a Sr Delivery head. The feedback was recruiter was on time and always kept me updated. The 3 rounds were completed within a weeks time and the offer was issued

I was working in another company when I contacted a very senior director for a role. He asked me to prepare a presentation on a mutually agreed topic for a discussion with the team. Believing his word, I spend nights to prepare a presentation amidst my official works. Now on the day of the interview, I get no call. I contacted the person, he said the following week they will schedule. The next week I was waiting for their call, but none came. I contacted the senior person again, but no response. Tried multiple times to reach, but no response. If UST Global is reading this, let me ask, do you think candidates who apply are that low that you can treat them like this. Everyone's time is precious. The effort put at least should have been acknowledged with a call. Please empathize from the candidate's side next time you do things like this. How much ever you grow, without ethics, its nothing.