If you are not on their Visa and if you still did not transfer your work permit to this company then you can simply tell them that you are not happy with the organiaiton and leave peacfully whats a big deal.
But if you are on there visa or you transfer your sponsorship in their name then you have no other option then continueing with them till you finish your contract.
You are claiming that the salary is Low, when you were offered this salary and if you knew that the salary that was offered is very low then why have you accepeted this job.
Wishing you all the luck for your career.
From Saudi Arabia, Riyadh