KFC Lawrenceville GA #023121 Kentucky Fried Chicken All I wanted was a simple refund for an overcharge.This is unbelievable!! Lawrenceville, Georgia

It's really very simple which is why I'm not believing that I'm having to do this. I ordered a 12 piece family meal while in town visiting my father at the hospital across the street. It was only knee surgery and he had no diet restrictions.
When we opened up our drive in meal with the rest of the family, it was an 8 piece instead of a 12 piece. I'm sure that the difference is only a few dollars. I called the KFC and spoke to the manager on duty. He immediately acknowledged the mix up as was already aware of it. He then told me that I would need to come back to the restaurant to receive a voucher for future credit. I advised that I had no interest in a voucher for future credit as I don't live in Lawrenceville and only expect a refund for the price difference. He refused. 
I then called KFC corporate and explained the above situation. This was 5 days ago.
I've heard nothing.

Again, just not believing that they are choosing to turn such a simple error into an Internet complaint along with the loss of a 40 year customer.  I'm sure that it's only a few dollars but dang.