If the old part wasn't defective, why were you replacing it? If there's nothing wrong with the part that was installed, the dealer will charge you labor for uninstalling the new part and reinstalling the old part. There could be many legitimate reasons that a new part didn't come in a box, so I'm not quite clear on what you think the problem might be.

You need to be talking to the dealer about your concern.

Depends on what part you are speaking of. Usually any electrical parts once installed cannot be returned for a refund. So it will depend on what part it is. If you are not happy take it back to the dealership and speak with the service manager and if you are still not happy, ask to speak to the manager of the dealership.

What part was it?

talk to the manager

I went to the dealer to have a part installed to my car and after the work was done I found out

1. he put a part on that did not come in the box and charged me for it

2. if I take it back to the dealer and get the factory part put back on can I get my money back