powder doesn't match My skin tone

I went to clicks Canal walk looking for a perfect make up, spoke to Lara who tried different shades on my face and we finally agreed with Mahogony shade in which I bought Loreal Infallable foundation and the powder but problem is we never tested the powder to check if it will go well with my foundation . Lara advised one shade in everything is the same to my annoyance it doesn't its very dark and it looks like I have app**** coal in my face not only did I waste my time and trusted a sales consultant I also lost R199 I could have used for something else. So I'm stuck with and item I can't return as per their return policy even though I was given bad advice.why hire someone who knows nothing about make up to assist your customers decide what to buy?