[second last payment of ...] or [two payments of ... back] or [two payments of ... ago]

I have made up the scenario below.

Suppose that Bill gives your charitable organization financial support regularly. He sees a special edition bill in a picture frame on the wall of your office.

(1) He said, "Where did you get the special edition bill?"

(a) I said, "It came from the second last payment of your financial aid."

(b) I said, "It came from two payments of your financial aid back."

(c) I said, "It came from two payments of your financial aid ago."

(d) I said, "It came from you two payments of your financial aid back."

(c) I said, "It came from you two payments of your financial aid ago."

I have come up with different ways of saying this idea. I am not sure which one makes sense. Thank you for your help.