Paid twice for 1 meal.

I bought a meal and paid using my card. Their card machine was giving issues and the first time the transaction "did not" go through. The cashier canceled the transaction and I added my pin twice. I found out that the first transaction that was canceled actually went through and was deducted from my bank account. I went to them and they promised to fix the issue. I provided proof and after many back and forths with them, they still haven't paid me my money back. I suggested that they give me a meal since I paid, but even to this day no feedback. Make sure that you pay with cash at that place!!