Subway held me hostage at the store while they tried to get their Credit Card machine working Corpus Christi Texas

I bought some wraps, chips, and sodas at a subway, and paid with a credit card. The lady printed the receipt and put it in the drawer. On my way out, the lady stopped me, and said, "Excuse me, your credit card No go through." So I let her try it again, unsuccessfully a few times. She asked if I had any other way to pay, and I told her "No." So she asked me to wait there while she called her manager on the phone to try to fix the modem, or something. She couldn't figure it out, told me to wait a little bit longer while she called this person, and that, and finally, after 45 freaking minutes, I was about to leave and the manager showed up and started playing with the machine until he could get it working, and charged me. I asked him for a discount, and he just said, "Sorry bout wait, sorry bout wait." I figured I'd complain on their website, explained I was held there for over an hour all together, and they just responded with a generic apology. Not even a coupon. Isn't that technically kid-napping?

Mason
Corpus Christi, Texas
U.S.A.