White Castle review: overcharged for my order

I ordered from the drive through. They said they were only accepting cash. I ordered 2 breakfast sandwich sliders and a small hashbrown nibbler. When I got to the window I sat along time while I watched the employee writing on paper. It was then I realized their register system was down. I had calculated the cost and came up with $5.77, they charged me $6.08. I ask how much they charged for each item. They charged me $1.89 for each item. The hashbrowns listed for $1.59. I told them how much they we on the drive thru menu but the drive thru employee said he didn't know how much they cost and he asked another employee and they told him all small nibblers were $1.89. I have no receipt since their system isn't working. I know $0.31 isn't alot of money but it's my money any how many other people will get over charged while there system is down because their employees don't know the menu prices.