What else can be done. Because it was unlocked when I first got it it

Carrier Lock; Though your Carrier is not obligatory to unlock your iPhone, but you may know it here --> How to unlock your iPhone for use with a different carrier ...

Activation Lock: If it is Activation locked, read here --> Activation Lock for iPhone, iPad, iPod touch, and Apple Watch ...

Nothing, sorry. Activation Lock cannot be bypassed. Return it to the seller and ask for a refund, or have the device recycled. It's useless to you without the correct Apple ID and password.