a. In case of a dispute over the amount of wages, the employer shall pay, without condition and within the time set by this act, all wages, or parts thereof, conceded by him to be due, leaving to the employee all remedies to which he might otherwise be entitled, including those provided under this act, as to any balance claimed.
b. The acceptance by an employee of a payment under this section shall not constitute a release as to the balance of his claim and any release required by an employer as a condition to payment shall be in violation of this act and shall be null and void.