I would go back to the quilt shop when she is there and explain that she didn't include the other borders and you are short. If she's customer-oriented she'll take back your piece and cut you a new one. It seems like it would not be a stretch for her to be able to sell the piece you brought back to another customer that it would work for.
If she won't take it back, I'd probably buy the new piece and sell the incorrect one here on the board.
Hope this helps!