It's the same in other professions. I'm in sales and applied for a job last week selling products I'd previously sold in the UK. Sent my CV and cover letter and received a call from the national sales manager saying that he was looking to interview this week and could I complete a questionnaire that would be used at interview time. I sent this off and the heard nothing back. I called him on Monday and he said he was a bit busy and would call back, he didn't. I called again Tuesday and asked if I was still going to be interviewed. He sounded flustered and said he would talk to HR and call me back, he didn't. I called again Wednesday and he said he was in the middle of building a showroom display and could I call back after 4pm. I did at different times and, due to going straight to voicemail, left messages asking him to all back so I could get feedback on my application. He didn't.
I was looking for work for 9 months prior to present job and rarely received a response to applications or to requests for feedback. It's not easy and you just have to keep plugging away. I am not enjoying my current position due to a lack support from my sales manager but will do the best I can as it pays the bills until something improves. I wish you good luck in your search.