Kpmg conducted phone interview almost 2 weeks ago then went silent. Should I call the person or keep waiting?

Hi guys, this thread is really informative!

I have a few questions:

1) I went for an interview at Deloitte two weeks ago, the HR person told me it would take about two weeks to proceed to the next step of the application process. I sent a follow-up email today and got an automatic reply that she is on leave until the 26th of December. So should I wait until after the 26th then follow-up with her again? Or should I contact another HR person to follow up? (she mentioned in the auto-reply email that I could contact one of her colleagues for immediate assistance)

2) I received a call from EY for a phone interview last week, I was busy when she called but she said she could call back another time. After that, I missed a few calls from her. Is it possible that she will call me again or my application would get rejected just like that?

3) Two weeks ago, HR from KPMG emailed to do the online assessment and request for additional documents (academic transcript etc), I completed the online assessment and send in my documents last week. I didn't hear back since, what is a good time for me to follow up?

Thanks for the reply!

Oh and btw, if I am rejected after the interview would Deloitte send me a rejection email or will they just keep silent?