Is a contract void if i never recieved a copy?

[Sarky]

You are NOT the copyright owner the photographer is.
Therefore YOU CANNOT publicly display the photographs without the copyright holders express permission.

"public domain". I very much doubt the image was public domain. Just being published or on the internet etc does NOT make it public domain. There is copyright invested in it and that belongs to the photographer unless assigned elsewhere.
YOU are NOT allowed to use it without permission.

The only thing which needs to be in the contract is whether you have the right to use the images and for what puposes. if there is nothing in there then you CANNOT use them.

Just because you do not have a copy does not nullify the contract. You are grasping at straws and you will lose anyway because you do NOT have any right to use the images unless specifically given that right by the copyright owner. Which from all accounts you DO NOT have.