Obviously a failure has occurred at your or their end. What you have got is the "Women's kilt, Billie style". Here you can obviously order any length between 15 and 20 inches. (The picture to the left).

The "Women's kilt" (the picture to the right), however, has a standardized length of 16 inches which is pretty short.

If you have ordered a specific length, they might think you ordered the Billi style kilt?

Have you asked them if it is possible to return the kilt, who ever of you is right?

I have very good experiences with the customer service of Heritage of Scotland.
Hope you'll find a good solution.

Greg