Make a list of the books you bought; go back to the campus book store and ask them what the price of each book was for the semester it was purchased. They should have that information.
You can still take the books if you know how much the cost. Go to the bookstore and see how much they cost, write it down. In the very unlikely case you are questioned, the IRS will believe a good faith estimate. Take a picture of the books.
Or if you want to pay taxes on the pell grant money, go ahead. It’s your money.
I see. I will look up the prices on the bookstore. They recommended I do that also. Thank you I know what must be done now.