Subway complaint: Double Order

I have the Subway app downloaded to my phone so I went on the app to place an order. At the end of the order I put my card information in and I received and error message, which led me to think that maybe something was wrong with my card. So I tried to order again but using a different card and received the same error message. I then decided to drive to my local Subway at 5795 North Market, Shreveport, LA 71107 where I live about 15
minutes from, to order and pickup my food. At some point the employees realize that they already received the order online but it’s too late because they already made the extra food. The Manager comes to the drive-thru and apologizes for the mix-up and states that when you get an error message online to call in to check to see if your order was placed. I order online and through other apps all the time and I’ve never had this issue. I ended up paying over $70 for food today with your company when I only wanted to spend the initial $35, is this a way to get more money out of your customers? I feel like I was wrongfully charged and it so now I will no longer use the app anymore! This glitch or whatever it is needs to be fixed because if not you will definitely lose more customers…we usually order Subway at least once a week spending over $20 each time but since this has happened it will definitely be a while before we order again l, if ever!!!