Lockheed Martin Contract Negotiator interview questions

2-hour virtual interview with 3 managers; very pleasant interview and was told I was a top 2 candidate; was told they would get back to me one way or the other by a certain date (about 10 days later), but I never heard another word, despite sending a follow-up email thanking them for their interest, expressing continued interest in the position, and stating that I look forward to hearing from them on the specified date whether they choose me or choose to go in a different direction. It wasn't until I checked the application portal a month later that I learned of their rejection that they never bothered to notify me of. Very unprofessional, inconsiderate, and disrespectful.