Burger King review: Overcharged and no receipt

My purchase only added up to $13.xx at the most but I was charged almost $18. I asked for clarification, even had the order repeated twice after being told it was almost $18. I paid and was waiting on my food when I asked for a receipt, because I was not given one, only to be told they can't give receipts at this time because of an issue with the machine. I sat with my husband at the table (dine-in) and added our purchase up multiple times and it only comes to a little over $13. On top of that, the food is not fresh. I am very disappointed in BK.