My ipad it has activation lock

If the Apple ID it's locked to is yours, you should be able to just log in with it. If you can't, it's an Apple ID issue, not an activation lock one.

If not, supply Apple with its original purchase receipt.

(173736)

Only the person who put your ipad in activation lock can remove it. It you bought iPad from somebody, return it because it's useless. If you cannot contact seller, most likely it is lost, or stolen, and you got ripped off.