I have a Lumia 520 with a ST sim. I never used one of these phones before and when I needed to put contacts in it gave me several choices but the only one that didn't require a sign up of some kind was the built in AT&T address book so I just started adding contacts.
Now that I've got about 200 of them, I want to back it up but it appears the only way to do that is to have an AT&T account which I went and made but it can't find my device. When I try to synch the phone to the account it says contact customer service. But whose customer service? AT&T or ST? I fear I might be unable to back this up at all due to the mix of an AT&T address book with ST service.