General Dynamics Information Technology Software Engineer interview questions

Interview consisted of about 7 people in a conference call. There were a lot of audio issues and I had to ask multiple times for them to repeat their questions. I received a tentative offer of 55k below average based on glass door. I countered, then they countered and bumped their offer by 20K. I brought my asking salary down to the average and told them I wasn't interested in accepting an offer below average wages. It was at this point that they decided to ghost me. I sent an email about week later asking where they were at. I was told they were no longer interested in me because I was "not interested in any compromise or negotiation." Seriously a courtesy email would have been nice stating at least that that is outside of what you are willing to offer. I don't really know what they expect people to do when you start with an offer that is 55k below average.