[mothered]

But can i use DNA if i sign that i received?

Yes you can.

As far as you're concerned, you didn't personally sign for the package.

And if i claim that i received the wrong item, wont they ask me to return it?

The certainly will.

You purchase a "stock" Item that weighs roughly the same and Is significantly cheaper, and return that.

Thank you for the reply, can you tell me what is and where should i get a stock item?

It's best to purchase It from the same company, using a different account altogether.

As such, when they scan It, they'll see It's part of their Inventory and assume they've sent that Instead of the ordered Item.