Initial call was normal. A day or two later I was given a task. The task required several hours of work and was given without any advance notice, with a same-day deadline. I completed it that evening and submitted it a few hours after the deadline, apologising for the slight delay.
After submitting the task, I received no acknowledgement that it had been received. I followed up twice over the following two weeks and did not receive a response or any update on whether the recruitment process was continuing.
I completely understand that companies cannot progress every candidate, and I have no issue with receiving a rejection. My problem is the lack of communication after asking candidates to invest this amount of unpaid time into a recruitment task.