1. How would mob dealers call or contact the Joker with a Joker Card?
2. I know the joker didn't make plans but what was his plan all along?

Ok...

1. They're the mafia. I don't think they'll have much trouble finding someone they want to find.

2. If you know the Joker doesn't make plans, why are you asking what his plan was? Obviously he didn't have one. I think his MOTIVE, on the other hand, was to prove to everyone they were too caught up in themselves to realize the facts of life.