Enter the Amount You Paid

I'm looking at the payment stub of my power bill.

The first line says "Please pay total amount now due --> $186.38."

The second line says "Enter the amount you paid --> $__________."

Does this mean I can choose how much I want to pay?

If not, why is my power company requiring me to rewrite an amount so that it appears twice on the same payment stub?

I think I'll write a check for $186.38 but write $1,863.80 on the payment stub. That way my lights will stay on and there's a small chance I won't be getting any more power bills until winter.