Client Class - Cannot Get Total Price To Recognize Surcharge

I am almost finished with my code. The only hangup I am having is that in my client class, I can't get the total price to recognize a surcharge.

This is my output:
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Your order consists of:

coffee, type mocha, size large, cost: $5.8
tea, flavor earl grey, size medium, cost: $3.6

The total cost of your order is: $8.4
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Notice that the total should be $9.4, rather than $8.4. It is odd because I was able to add a surcharge to my coffee(50 cents), and it does in fact recognize it when calculating the price of the coffee. So why won't my totalPrice in the client class recognize it?

Here is my Client class:

public class CoffeeShop {
public static void main(String[] args)
//One coffee
Coffee coffee = new Coffee(16,"mocha");
coffee.set_price_per_oz(coffee.size);

[Code] ....