Hi there
I’d be happy to help with your contacts.
In order to recover contacts from a lost device, they must have previously been backed up. I would recommend trying to log in to AT&T Address Book with your AT&T account details. If backed up, you will see your contacts listed. If not present, I would also recommend trying Google Contacts where you can log in with your Google/Gmail account if you have one. Your contacts may also be listed here.
I hope this helps!
Charise