McDonald’s complaint: Overcharge wo rectifying

I went to this McDs on 51922 about 9:45pm.I ordered 4 McChickens, 2 wcheese, a McDouble. The order totaled 14 plus change. I said it was too much and the screen was wrong. The ordertaker read what was on her screen and said the total was 11 plus. My screen still showed 14 plus. The total should’ve been less than 10 (1.39×2, 1.00×2, 2.49, plus 2 slices cheese). I told the cashier, he agreed. He said he couldn’t change it, I’d have to pay 11 plus. I asked why if it overcharged. He said their prices went up. I said I shouldn’t have to pay an overcharge. He said he saw the problem and couldn’t fix it, I’d have to pay it to get my food. I asked for the manager. He left, said the manager was busy on the line bc they were short-staffed but they said I had to pay or not get my food. I said that was wrong. He said I can either pay it, not pay it and not get my food, or deduct food to get the amount I wanted to pay. I felt hurt and taken advantage of by this franchise for profit. I came from out of town to stay with a friend bc I experienced gun violence that day. It was late, I was hungry and I left wo my order feeling even more anxiety. My friend took me to another McD’s and the order totaled 7.29, wo the 4th McChicken for 1 dollar, a BIG cost difference!! I have the receipt and pics of the price screen of the McDs that tried to overcharge. My friend said that McD’s always overcharges. What will be done?