Urgent!!! Where is it?

I have lost a receit and it is very important I find it because if I dont I wont get a larger sum of money back I am really worried I threw it away, my other theory is that I left it in a book.

http://i46.tinypic.com/2w2ms1u.gif

POF is in the 2nd house unaspected,if it means anything

Also, I think it might be either in a book of mine,or in some other document,or I fear I have thrown it away
I remember seeing it in my student grade-card, but I dont remember what I did with it, but I dont believe I threw it away.

It is a receit from an auto-school, I paied for lessons but due to my obligations I canceled my classes and the only way they can give me back the money is if I give them the receit. I have already signed all the paper and they have the bank account number to which to transfer to money to, but I cant believe I lost the receit

Note: Shortly after I made this horary, I have found a receit in my wallet, but it is my brothers. I am looking for mine,which is identical.