Product not suitable for specified cameras

Have a Nikon Coolpix S31 which although they should fit into the camera, according to the Czech stating Navitech, definitely not fit in. So I was able to send them back only. The return runs very unusual, throw them into the mailbox with no return address and no return code. They have no evidence in hand and can only hope that the return arrives after UK. The contact until now works fast and friendly but I am unsure whether the return so arrives and I get my money. I still have to wait.