Want to export/save/backup contacts and AT&T address book issues

[CaptainLumia]

I have an unlocked 520 I've been using for some time now. Because it is an AT&T branded phone, it came with the AT&T address book as the default address book and it is what I've been using. Between the time I purchased the phone and now, I've changed carriers. I can still see all my contacts, but because I no longer have an ATT account, I cannot login to their app or website and export/download/save my contacts.

Is there a way to copy all my contacts, or export? I have a Gmail and Yahoo account. I also have an MS account, but when I login to my MS account, none of my contacts in my ATT address book show up.

I downloaded the app: "Transfer my Data" (MS Mobile app)
But that only seems to work to transfer to another phone.

Thoughts?

 

[TechFreak1]

Have you tried going to into an AT&T store, maybe they can help?

 

[CaptainLumia]

No, I might do that as a last resort. I doubt they'd be too thrilled to assist someone who dropped them as a carrier and wants to transfer to a non-AT&T phone from my existing. But it is an option on the table.