My question involves labor and employment law for the state of: Virginia

I'm looking for professional advice regarding my company's tuition reimbursement policy. As a full-time, permanent employee, you are eligible to apply for tuition reimbursement and, if approved, the company pays 100% of the cost. One of the stipulations is you must remain employed for 18 months following the end date of your most recent COURSE (not degree). This policy is only in effect if you, the employee, voluntarily terminate your employment. If the company terminates your employment for any reason (misconduct, lay-off, etc.) you are not required to reimburse the tuition dollars. I completed my Master's this past November (yeay!), so I know I am on the hook for repayment through May of 2019 in order to be "home free." I am planning to resign in the near future - thus making me responsible for the repayment of about $15k.

All of that said, there have been multiple employees who have voluntarily terminated their employment with the company (some in past years, the most recent being this past March) and their tuition repayment was waived. It's sort of like an "oh, we forgot" or "eh, it's only a couple thousand dollars" attitude they take with some people. Regardless, it's discrimination, right? To require some folks to repay the tuition dollars and not others...

I'll go ahead and answer what I think many of you will ask - yes, I do know for sure this is going on because I work in the HR department and I'm the one who processes employee paperwork. When I terminate my employment, should I be saying to them that I won't be repaying because it's a policy not enforced for all? Any thoughts/suggestions/advice is very much appreciated!