What does overpayment mean

An overpayment is your refund, it means that you overpaid your taxes and get money back.  If you see a question that asks if you want to apply your overpayment to your next years (2017) taxes, you want to say that you do not want to apply the refund so that you will receive your full refund this year.

How can I change this to get my refund for this year?

I incorrectly did the same thing how can I change this to get my state return this year. It still indicates pending

Overpayment: the government owes you a REFUND because you overpaid your taxes