It really depends on how the leave policy is written. Some employers allow employees to borrow leave time from future accruals, with the intent the employee will stay employed at least long enough to satisfy the arrears. When the employee leaves before the arrears are satisified, it is likely the employer will require reimbursement, usually deducted from the last paycheck. The employer attempted to accommodate your need for more leave time, so it is not uncommon to have that money repaid to the employer if you leave before it is earned.