I was thinking that maybe she could have forgotten to take the phone charger with her on vacation and the battery ran out, but thinking about it, it can't be that as her phone would not ring if the battery was dead or the phone switched off. So she has either left her phone behind at home or if she has the phone with her, then she has been ignoring my calls and messages. If her phone was in a no signal area I guess when I ring I would not hear it ringing and it would sound like it's switched off?