Why is my iphone stuck on Activation Lock

Here is the Apple Support page for Activation Lock. Find My iPhone Activation Lock - Apple Support

If you are not able to find the original owner, or able to get them to remove activation lock, then there is truly no way for you to use that iPhone. And if that is the case, I would recommend you try to get your money back, if possible.

Have the seller remove the activation lock:

Turn off Find My iPhone Activation Lock - Apple Support

If they will not or cannot do it, return the phone for a refund. You will never be able to activate that phone.

Hi

Activation Lock prevents unauthorised use of the iPhone if it is lost or stolen.

This can be disabled only by the previous owner (who may not be the seller) either entering their Apple ID and password on the device or by them removing the iPhone from their devices list in Find My iPhone via iCloud.com.

If you cannot arrange for either of these steps to be taken, then you will be unable to use the iPhone and should return it for a refund.

There is no way around this security feature.

If you purchased the iPhone via a website such as eBay, if it was misdescribed by the seller and the seller cannot be reached or will not remove the lock, consider lodging a claim (eg under the eBay Money Back Guarantee).

More information and instructions:

Turn off Find My iPhone Activation Lock - Apple Support