Well, first of all, this seems like an amateur mistake. I would never make any Newton's cradle-related ordering mistakes. I would keep sending emails over and over again until you realise you're emailing the wrong address, at which case email the right address and ask them where the Newton's cradles are.

In the meanwhile, that's a lot of wooden planks from all those cradles. You could take them apart and do some DIY. You could build... Uh... A shelf?