McDonald's not giving me a refund .

I went there to buy a meal which was a Double big Mac , regular fries and a cappy apple juice so i payed by card the first time i thought i took out the card earlier than the machine said so when i payed again it did the same thing so that's when i realized that i payed for two meals so i asked one of the ladies to cancel my first order then they said they'll talk to the manager but when they talked to the manager it said my food is already made so they cannot redeem it for me but my food about 10 minutes later to my table so now i had to go with two meals and i ate one then made the other one a take away .