The mobile phone companies are loaded (just like the UK government). All these excuses about costs and no magic money tree is rubbish. It's the distribution of the wealth that's the problem.
As for the phone. Can it be tracked when the phone is off? I know it can be done if a phone has the right software 'hack' on it. But not sure if it can be done retrospectively to any device (I would say no). I know the tech is there though.
The account of the trial I read said that a Whatsapp message sent to Lindsay's phone at 4.30pm on the day of her disappearance wasn't delivered.
Which would indicate that the phone was out of battery, or had been turned off sometime before then. The last known time that she used the phone was at 3.41pm (before she left her house) when she replied to a message from her boyfriend.
That's all us 'websleuths' have to go on so far. . . .
I should think at the very least they'll know when the phone went 'dead'. I would also think that living so close to where she went walking Lindsay wouldn't have taken a phone that was almost out of battery with her.
Someone on here said her phone was 'dead'. But as far as I know that hasn't been reported as being official.