Thoughtworks Backend Java Developer interview questions

First they did a Skype interview, and then they sent me a Technical Assignment composed by 3 complicated problems not easy to understand, and no easy to solve, and no a common problem that you can really face in a job. They gave you 3 days to solve it, and if you cannot they can give you some more. In my humble opinion, the thing is we have daily responsibilities, and in my case I was not able to dedicate to it time, I told them ain the way I solved it, but it was not enough for them, they want the java files with its Junit file with one of the problems solved and working, so they offer to me some more days to solve it, so I found myself obliged to do it, but with no time, I had to search on internet a bad practices way to solve it and changed it to good practices as I can and sent to them, for to sent them something.... They answered whit a phone call form HR she said to me that I was not approved and call them back when I will done some reinforcement course.... That is a bad way to treat people, firs respect to the to the others they do not really know me for to say that, and I told them.