Bad service

I bought a mirror online and I had a discount, on the day of collection at decofurn in Boksburg I decided I wanted a different colour. The process of just exchanging the item took me 3 hours and I am not exaggerating, it took that much time and on top of that they decided that I need to buy the mirror using the original price (basically they not considering the discount). I have never heard of that in my life I am very disappointed. I definitely WILL NOT be buying from them ever again.