[humorousSwift]

Won't they ask me to return them back? You mean to say that they have made a mistake and sent me other shoes, right?

Correct.

You'd purchase a very cheap Item from Adidas, and claim that you received that Instead of the one you've ordered. When they request the return, send the (cheap) wrong item.

As i said at the beginning ive ordered several things to do the partial empty box method, but in the end they arrived separately so the products are no good for me.
Could i say that i have received two hats/backpacks and i have not received the shoes? And will it be ok if they see that the weight does not match the weight of the shoes?