American Furniture Warehouse Return policy not followed- would not credit back full amount based on their error gilbert, arizona

I purchased a king size box spring from American Furniture Warehouse. When the box springs (there were two due to the size) arrived at my house, my Fiance mentioned to the delivery people that the box spring set was too long. The delivery men responded with "you may need to get a new mattress or new bed frame to fit". Granted, I was not home at the time of delivery, or I would have rejected the delivery due to the incorrect size (I measured it when I got home and turns out the mattress box spring set delivered was for a CALIFORNIA KING not a king. First of all, I just purchased a new king size mattress and bed frame, totalling $2,300. There was no reason for the delivery men to see that it was the wrong size and yet still drop off the INCORRECT item. I called American Furniture Warehouse to ask for return options. I was informed by a very rude customer service agent that I would have to rent a Uhaul and return the box spring myself. (which is absolutely ridicolous based on their error). I then called the actual location where the item was purchased via the phone (in Gilbert, AZ) and spoke to a nice Manager who stated that the box spring would be returned the next Saturday and a full refund would be placed back on my credit card that the item was purchased with. I thanked him and thought that would be the end of my dealings with American Furniture Warehouse. A month later, when my credit card statement came in the mail, I noticed that there was a difference of $69 between the item purchased and credit that was given. Long Story Short: DO NOT BUY from American Furniture Warehouse. Unless you want a headache, two saturdays where you have to stay home waiting for their delivery men and hours on the phone trying to attempt to get a measly $69 back. They DO NOT honor their mistakes and they do not believe in putting the customer first. I have never been treated so horribly and have never felt so dumbfounded as why a company would not stand behind (or at least try to rectify) their mistake.