AutoScout24 Junior Fullstack Software Engineer interview questions

Applied on LinkedIn. Given 40 min online coding question (Codility) Quick response asking for an interview with hiring manager/HR rep. Had an interview and it seemed good, interviewers were friendly and easy to talk to. Very quick response after interview asking me to do a technical task. After I completed the technical response I asked to verify that they received my submission. No response. One week went by (nobody pulled code from GitHub) and I had to email two different people before receiving a rejection (I'm not even sure why). Have a feeling it was a boiler plate response. My impression was I was guaranteed a follow-up interview to talk about my submission or even they'd pull the code to test... Poor way to handle it. Quite annoyed. My advice is either don't interview here or refuse to do the task.