Makro Refuses to exchange a Christmas gift

On 06 December 2015, a camera was purchased & given to me as a Christmas gift & this was only given to me on the 24 December 2015. I found this to be not compatible to me & went to the Makro Store at Centurion to have this exchanged for a better & more expensive unit & was advised that this was not possible. The 14 working day was on Christmas day & the store was closed. I could not go on the 26 December 2015 as this was also a public holiday & therefore had to go on the first business day of 27 December 2015. I require intervention & also the unit to be exchanged, urgently. I am also of the opinion that this is a big store and always look after the customer needs favorably. Awaiting your urgent response.