Is it permissible to take the difference in entitlements for overtime hours from the company without its knowledge, given that this difference is significant and was not agreed upon beforehand?

There is no objection to an employee taking their financial right stipulated by the employment contract if they are denied it and there is no legitimate impediment to doing so, provided that taking it does not result in a greater harm than the harm of losing the right, and provided that it is impossible to obtain the right through legal means. It is not permissible to seize company funds for overtime work unless the contract stipulates additional pay for it, or custom dictates it, and the work was not voluntary, and it was impossible to obtain the right except through this means.