Remove activation lock up from my IPAD

Return it to the previous owner and request your money back. He is the only one that can release the Activation Lock. No one here or at Apple can help you to get it released in any way.

When someone tells me a story like that, I immediately figure it is stolen and back away from it as fast as possible.

In case you want a second opinion. You cannot bypass activation lock without the owner who put the lock on the device. If they can't remove the lock, then you own a totally useless device. Apple won't help you. We can't help you.

Why is the previous owner unable to help?

Get your money back or recycle the device or use it as a paperweight.