"C" for Crusade

I am on a crusade.
This particular crusade is against our inept, incompetent, indifferent and (unfortunately) ONLY grocery store.
Probably better than 30% of the time we shop there, we are either over-charged or an item is double-scanned.
I have spoken three times to the store manager and written several emails to the corporate office. Each time, they apologized for the error and promised to fix the problem(s).
When I spoke to the store manager, he gave me the item for free. I'm not interested in getting stuff for free, I just want them to get it RIGHT!
Right now, in fact, there is a $20.00 gift certificate with my name on it waiting at the customer service counter as restitution for all the screw ups. I wasn't going to pick it up, but after being over-charged again today by $1.50, I changed my mind.
I've never before encountered a grocery store that was so consistently screwed up. If the wrong price isn't programmed into the computer, the check out person enters the wrong code or double-scans an item.
Maybe I'm the only person who checks their receipt, but I doubt it.
What really freaks me out is when I bring a glaring over-charge to their attention at 5:00 in the evening and they act like I'm the first person who noticed all day!
My neighbors and co-workers don't shop at our local grocery any more. Without exception, they all say they drive 12 miles down the road to shop at a different store in a different town.
I'm not ready to do that yet.
I'll gird my loins, saddle up my trusty steed and carry this battle to the state attorney general's office before I furl my flag and sheath my sword... so to speak.
Besides, I find certain pleasure in hitting them over the head with their own mistakes again and again. Ain't I a stinker?!!