You're right. There should be records somewhere. I don't know how much data they keep or for how long. Do they know what you have programmed into your phone as regular numbers? Can they see your photos?
I don't know phone technology in today's world. They have a ton of data on them, but I don't know how much of that is kept on phone company records, and how much is only on the phone unit itself.
I doubt that the company can see photos or the content of text messages. But they certainly do log calls.
Of course, anything lost from the phone that's not retrievable through the service/network provider is a big loos, but the big point as to when was the last time either of these women used their phones for talking is still the most important aspect of the phone.
From personal experience - some friends were being investigated by the feds. Voice mail messages from over a year earlier were retrieved.