Incorrect Powder Shade by a professional

<p>I purchased a MAC powder at Edgard Menlyn after i was tested by the professional lady who is supposed to know what she is doing,when i got home and used the powder i found it to be the incorrect shade, i am not able to use it as it makes my skin look dark and i dont think it is fair that i paid so much for something that i am not able to use,.</p>