Okla. Stat. tit. 74, § 1734

If an eligible employee on whose behalf payment has been made pursuant to Section 4 of this act terminates service with the payor agency prior to the expiration of the required payback period, the employee shall be required to reimburse the agency for the amount of the qualified education loan expense. If the employee performs less than the number of hours of service required for the full amount of the expense paid, the agency shall be reimbursed on a pro rata basis based upon the actual number of hours of service performed by the employee.