What does it mean to return maternity pay on pro-rated basis?

My company's policy says that if I take maternity paid leave but leave the organization before my contract ends, I will have to reimburse the pay on a pro-rated basis. What does it mean?

Thanks!

If they paid you 300$ per week for 20 weeks, they paid you 6000$.

If you only stayed with the organization for 10 weeks you owe them for the difference. 3000$. That is the pro-rated amount. This is an example.

It means that you have to pay back what you got. If you get 6 weeks of paid leave but are only paid for 4 weeks before you leave the company, you would need to pay back only 4 weeks.