ISBN is different on the cover from the one Amazon gave me.

I'm publishing a book on Amazon KDP. I'm publishing Kindle and paperback books. Amazon assigned me an ISBN, which I copied into the front pages of the book. But when I received the proof copy, the ISBN printed on the back cover is nothing like the ISBN Amazon said they have allocated me that is still showing in my Amazon account. Will the non proof copy have the correct ISBN, or how do I fix this?