Labcorp Specimen Acessioner interview questions

Applied for this position since the hours were perfect for part-time work. Arrived 15 minutes early, but was left to sit in a room for over 30 minutes while the interviewer sat in her office instant messaging. I know this, because you could hear the pings going off while she typed away. Once she finally entered the room her attitude was very uninterested and casual. I however was determined to land this job so proceeded to give it all I had. Once the interview got going everything was going great until I was asked by her if I had any issues with staying past the 11pm scheduled shift. I told her I didn't mind being a team player and helping out every once in awhile, but I do have a full-time job and couldn't make a habit. After saying this I could tell from her attitude and disposition that I wasn't going to be hired. And I wasn't. I thinks it horrible that I was denied this opportunity, all because I wouldn't agree to continuously work past my scheduled shift. If the company knows they regularly have late specimens come in, then they should hire staff to accommodate those hours, not punish people.