How to get exit visa from sponsor in Saudi Arabia

Hello sir, I am working in Saudi Arabia currently. I had signed a contract of two years, my contract is finished already .. Now I got a good job offer from another company in Saudi Arabia. When I asked for exit visa from my sponsor he refused to give me exit . My new company sponsor says that he can't give me visa until I get exit from my old sponsor. So please advise me how to get exit visa from my old sponsor to join in the new company..