I bought a used Honda Civic three months ago, The...

I bought a used Honda Civic three months ago, The dealer did not put the license plates on, just a Serramonte logo. I got the pink slip and registration within two weeks, with a license plate number. I never receive the plates. I went to DMV to check. They told me that a used car should have the license plates on, and DMV cannot issue another plate. So the license plates should be in the dealership but they did not put it on the car for some reason. I called the dealer but they said the plates should come from DMV and I should wait! I don't know what kind of dealer is this.
So I have no choice but paid $21 for a new license plate with new license number. What a bummer...