Usermind Data Scientist interview questions

I interviewed with HR and Vishnu, their Head of Engineering . Vishnu said that, moving forward, he would send me a coding challenge. Coding challenges are common, but typically they aren't supposed to take more than a few hours and usually don't require the use of cloud computing, which takes awhile to set up and is expensive. Vishnu and I discussed and agreed on standards for the coding challenge - the data wouldn't be very dirty and it would be small enough to run locally so that I could complete it in a few hours without using cloud computing. Well, I received the challenge and the data was too large to run locally. Furthermore, there was no legend explaining what the columns in the csv meant. They also wanted me to prepare a 30-40 minute presentation on my findings. I emailed Amanda at HR explaining that this was pretty non-standard for an unpaid coding challenge. To do a challenge with proprietary data that was too large to run locally I'd have to use cloud computing and it probably would take longer than a few hours. I'd need to be paid for a more labor-intensive coding challenge. Alternatively, I offered to do the same coding challenge on a subset of the data that I could run locally. I also asked, repeatedly, if they could provide me with a legend for what the columns meant, as well as a time estimation for long Vishnu thought this should take. They refused to answer any of my questions saying it would be "unfair" to other applicants who allegedly didn't have any problems. And they refused to pay me, or reduce the size of the data from 4.5 million rows to 1 million rows and then told me 'this isn't the right fit/we need to part ways'. I've done a lot of coding challenges and I've never had an experience like this. Every other company that's sent me a challenge answered my questions, gave time estimates, didn't require a 40 minute presentation, kept their data under a million rows--meaning it would be easy to run on my home computer--and provided me with a legend explaining what the columns in the csv mean. I've been paid for coding challenges that were on large proprietary data sets and/or required extra time. This behavior was quite non-standard and really unprofessional. You have to respect peoples' time, answer their questions and offer support when you ask them to do unpaid work. Furthermore, I had an agreement with Vishnu about what the challenge was supposed to look like and it didn't meet those standards. It doesn't seem that Usermind understands Data Science recruiting or cares about respecting and supporting candidates. Too bad because I have professional experience doing exactly the kind of Data Science work that they focus on (click stream analysis to determine user intent) and they refused to work with me on modifying the challenge or giving me the support I needed so I could do their challenge in a reasonable amount of time without using cloud computing.