Sonic Drive-In complaint: Gave wrong order

A friend and I are working in Prewitt NM so we currently live in Grants NM we work Mon-Sat from 6:30am to 5:00pm in the solar panels so you can imagine how tired we get out of work. Today as we got out we headed straight to Wal-Mart for some essentials then to Sonic because we where starving, we made two separate orders so we could each pay our own food, an employee came outside and asked your the two separate orders correct which we replied yes and we each gave our cards to pay so she went back inside about 5-10 min later the employee came back outside with our cards and orders to which I asked if it was everything and she said yes so we headed home, we got home and got our orders out of the bags and I find out they gave my friend her order correctly but mine was wrong I checked my account and sure enough I was charged $7 instead of the $14 which was supposed to be my total now I know everyone makes mistakes but what really angers me is that I called the location to let them know and the employee who answered me made it seem like it was my fault stating that yes the order was there but it still wasn’t pd for when I gave my card to the employee who went outside so she could charge it, I don’t see it in anyway my fault the business should be in control of the orders and vehicles outside and the worst thing is that there was only 1 other truck on our side when we got there so its not like they can say oh there was too many cars sorry on top of that the stalls are numbered so of course I asked for a refund because like I said we are all day working the only thing we want after work is to eat shower and sleep I was not gonna go back to Sonic when I had gotten home already and now I have to wait a couple of days to get my money back. I will not stop anytime soon at Sonic again and I am making this complaint so the employees pay more attention to what they are doing and hopefully get my money back soon. I will be uploading the receipts where you can see the times of the orders they are about 6 min apart when we made the orders at the same time.