activate i phone 6plus A1522

Trying to activate an iPhone 6plus. I'm a Verizon customer. This is a "non-verizon" phone that is unlocked. A friend of mine who is on t-mobile, put her sim card in and it worked immediately.

Things to know:

Model: A1522 CDMA

New sim card for me? Check

Reset everything (networks, erased, etc)? Check

All updated to current software 9.3.1 and Verizon 24.0? Check

Network is still reading: Not Available

However, for 3 minutes the other day, it said, Iphone activated and it worked. Since then, nothing.

Has anybody experienced this or know how to fix it?

Thanks!

Jeremy