Sold damaged goods as new

On 2015-05-19 we bought an IMAC 21.5 ME086 machine R18.999) from Incredible Connection Centurion Mall. On arrival home, we noticed the keyboard was used, dirty and still had glue on (I assume it is the stuff they use to stick it to the display shelf, and the mouse was also dirty. To top it all, the screen had a chip out on the right top corner. When my husband asked the sales person why the box was open, he explained that he had to open to box to check to content thereof. When we returned the machine the same day, the assistant sales manager made the excuse on behalf of the sales person saying that he was supposed to check to content before it was given to us but this was not done otherwise they would have picked up that this was not a new unit.He also confirmed that the machine was taken off the display shelve because it was damaged. They apologised and said it was a mistake and that they are sorry about the inconvenience. A new machine was delivered the following day. I sent through a written complaint to Head Office and only up till now received an automated receipt of complaint from them and no other feedback. <br> Really? Should we accept to apology of a mistake made and move on?