Unauthorized use of mobile device (netgear nighthawk)

Unauthorized use, and blacklisted are vastly different. 

What plan is/was it on? 

When I spoke to AT&T rep they indicated it was reported stolen 3 days from the date I called, which was Saturday.

If the store reported it only they can remove it.  Go back to the store and have them look up your records, your purchase receipt.

We'll be happy to look into the status of your device for you @bbyrd.

As @formerlyknownas mentioned, blacklisted and unauthorized use are two different situations that would determine how we'd proceed. Which plan were you using this device on? Was it active on our network?

With more specifics, we'll have a better idea of what we can do for you. We look forward to your response.

Darais, AT&T Community Specialist

The plan I had was the 100G $55 per month prepaid, yes the device was active on the At&T network.  The prior owner of the device reported it stolen, which they should not have being I paid for the device. Your welcome to contact me.

Thank you for responding @bbyrd.

Since you are not the original owner of the device and you didn't purchase it directly from us, we would be unable to assist in this situation. Your best bet would be to return it to your point of purchase.

Darais, AT&T Community Specialist

Prior owner? 

You take chances with 2nd hand.  If the place you bought was a pawn or second had shop, only they can help