Have active sim for Net 10 on AT&T phone but no sercice

[cdgates]

Hi anyonphone that could help!!
I have purchased a refurbished A T&T iphone 5s from Amazon. (supposed to be unlocked) I purchased activation kit and placed nano sim in phone. Contacted net 10, ten times now followed the turn off/on try to make call part and no service. Was finally told may not be unlocked phone. No one can tell me how or why no service. On phone the carrier says TFW18.1 if it means anything. Can anyone give me a link or idea how to fix problems.

[JavierNT]

Good afternoon. My name is NET10 Javier and I’ll help you. Please check your Forum inbox for an update. Thank you.