Bad service - Woolworths Beauty in Somerset West

On Saturday afternoon I visited the Somerset West Woolworths beauty branch. I informed the lady that I would like to buy the Estee Lauder double wear foundation but I don't know what my shade is. She tested a shade on me that looked perfect at that moment because of the light I then bought it. So today I started using it, and only then I noticed that this shade is too dark for me. I called the branch to check if whether they can exchange it of me but I was informed that you don't do foundation returns. I don't understand how you guys can not when one of your employees is the one that chose the color because obviously when I go to one of your stores I would think that i am being assisted by a professional who knows about their products. Now what I am supposed to do with a dark shade of foundation? So my R625.00 will just go to waste even though this is not my fault?