where did you order it from ?
if this is an amazon thing the kindle books and the paper books are totally separate things.
Its not like you buy it and then decide how you want it. When you select the item it is either paper or kindle and they are totally different items.
Now if you think that you ordered it as a kindle they might mean delivered as being ready for your kindle to download. But if there was anything about shipping in there you got the wrong item.
what you have to do is fill out a return report
the fact that you expected it on kindle is reason enough to return it
once you fill out the report it will allow you to print shipping labels and you just have to put them on the package when you get it and give it back to the post office.
There is no charge for the shipping and they will refund your money.
then you have to order the book on kindle.