Kohl's store can look up your charge credit card that is with Kohl's only but not other credit cards.
So if you have a credit card with Kohl's and cannot find your credit card they can look up the Kohl's credit card you have with them so that you can make the purchases.
If you just got your Kohl's charge card you can shop with the temporary number without having to have your regular charge card through Kohl's.
Then when your regular Kohl's charge credit card comes in the mail and you activate it the temporary number will not longer be valid or active.
You can then use your Kohl's credit card through Kohl's but only for Kohl's stores and online at Kohl's.