3M Data Scientist interview questions

Phone screen with hiring manager and a technical person. Same day asked to do a work sample. I made a point of rearranging my schedule to find time to do the work sample. A week passed with no contact and I had to email the hiring manager to get an acknowledgement that they received my work sample. I do get a response saying I will receive feedback "shortly". A week later I get an automated email telling me I am no longer being considered. I wait a couple days figuring the hiring manager would contact me with some more info. I eventually emailed the hiring manager asking to get feedback from the work sample. I never even get a response from the hiring manager. Maybe I'm expecting too much, but not responding to candidates with simple requests seems unprofessional to me. I'm left not even knowing if they looked at my work sample. That's a really frustrating outcome for someone with a non-traditional background for data science. I don't know if I need to strengthen certain technical skills or not. I certainly would think twice before investing time into 3M's hiring process again.