BD interview questions

I applied for the Development Program for the Inside Sales Role. Started with an interview with Regional Sales Managers, who wanted me to continue with a panel/presentation interview. Regional Sales Managers gave me a few names of current employees who can help me prep for the next round of interviews. None of the employees answered back, so I was expected to present and prep on my own without a bit of guidance. Panel interview was okay, pretty basic/behavioral questions asked after. I sent a follow up email still expressing interest and requested some feedback. Hiring managers went ghost. Not even a rejection email. For a large and successful company, you would at least expect them to be decent and email back stating that they will not be moving forward with the application. This creates a sense of distrust in the hiring process of the company and a lack of professionalism. Being in sales requires one to be communicative. Kind of ironic they lack to inform and communicate.