I came across a Jack in the Box in some Los Angeles suburb (very vague I know) that did this. The receipt looked identical for the card processing with the fee line then discount line. If you use PIN-Debit, you will pay the fee.
You are lucky. Up here in Nevada where I am, we have a Dairy Queen in Carson City, NV and in Reno, NV who has a creatively worded "employee service fee" that applies a .59 charge to every transaction. However, if you pay with cash, you will not be charged that fee. It is a card fee. Receipts are frequently not issued and they quote you the total before the fee, then if you pay with a card, the fee gets tacked on and shows on the receipt as "ESF" so when you send it in to the complaint area of Visa or MasterCard it looks like "another item" on the receipt. Very shady business practice. I also lodged a complaint with Dairy Queen International (franchisor) who basically told me the locations are independent franchises who can do whatever they want.
The sign is suspiciously similar.
https://www.google.com/maps/uv?hl=en...9WqR5afs2Rzo6P