Anybody accidentally recieve someone else's order?

I ordered the DX9 Leader Megatron upgrade kit from Captured Prey. I got the package but didn't open it for a few days. Get an email from Captured Prey that I might have received someone else's order and to confirm. I open the package and indeed it was not mine. I emailed them back to confirm it and haven't heard back in 3 days. Not sure what I am supposed to do now. Just wait until they get back with me? Email them again? Just send the package to the person it belongs to? The package I got contained a FT Tesla and KFC MP-22 hands.