If your E-junkie Cart shows "Current Promotion", that indicates a discount is being applied automatically because you have set up that discount without any Discount Code. Note the difference between the Discount Name (which our system uses to tell one discount from another) vs. the Discount Code (which buyers need to enter in their cart manually to claim the discount).
To find this automatic discount in your E-junkie Dashboard, go to Manage Shipping, Tax, Discounts > Discount & Gift Coupon Settings, click the dropdown menu under Current Discounts to view a list of discounts you have set up. Selecting a discount in that list will show any code(s) set up for it, so you can find the one with a blank under the Code column. Then you can either click View/Edit next to that discount to add a Discount Code to it, or tick the box next to it and click Delete Selected Discounts to remove it.
TIP: If you have a lot of discounts to look through, you can click the Current Discounts menu and then just click that menu again to collapse it, which will then allow you to use your keyboard arrow keys to scroll through the menu and view details for each discount, until you spot the one with a blank Code.