Amazon Non Software Development Engineer interview questions

I applied at a software development engineer for Amazon Web Service, in Dublin. Initial contact was by email, all nice and well, and they told me they will send me a "coding challenge" at a given date (still by email) to complete in one hour. Fair enough, I've heard of those before, it's usually a strictly algorithmic problem to solve in the language of your choice, and this one was no exception (see below) Came the big day, I sat ready in front of my computer, and... nothing. They forgot to sent it. I had to call to remind them. Okay, this is the kind of thing that happens. Anyway, I completed the challenge, with a working solution, maybe not the most optimal, I admit, but working nonetheless and in time. After that, no answer from them, not even an acknowledgement they received it. Days, then weeks have passed : obviously, they give you one hour to do the code, but allow themselves unlimited time to have a look at it. I tried to contact them again, with no avail. I'm not the kind of person who harass people on the phone/mail, so I gave up. I'm not that desperate for a job. In the end, I'm really disappointed by the lack of professionalism, especially from a big company that boasts being constantly on the edge. It's like they didn't care.