What time is an employee given to transfer working residence permit from one company to another?

Hello! My current company with a Chinese company expires with one week, they they haven't provided me with the letter of release or any other documents that I need to do my visa transfer. On the other hand they require me to give them my passport right after the contract expires in order to cancel my residence permit. In this situation how can I transfer my currentresidence permit to another company if the old one doesn't give me any time for it and the new one is saying that it will take a month. Is this part regulated by Chinese law somehow and does it mention what period of time is given to employees in order to transfer their visas.