隻要你在公司幹的好，他們就不要求你退這5000塊

How do I knew?
I did it.
I told them not need send me the last pay check, use it as the pay back of my sign on bonus.
But, HR said, our VP said LaoTu did a great job, he does not need return that $5000 sign bonus.

Except passport and drive's license, everything is negotiable.