Complementary colours are pairs of colours that contrast strongly when compared to each other.
Black and white are neutrals and not colours at all, and therefore they cannot be complementary colours... white shows the presence of light, and black shows the absence of light. Black and white areas next to each other do demonstrate high contrast, but high contrast gives a different visual effect than complementary colours do in a picture.
Check some of the forum discussions on complementary colours for suggestions on using colour for contrast.
Not fussed on the composition of this shot, but the thing that I think will really hurt this image is that you have entered a B&W image in a complimentary colour competition. Hope your not too offended by this score, but I want to be straight up and explain why I scored your mage like this 1/10
Black and white are not complementary colors. They are contrasting, but not colors at all. This would be effective (despite the "does not meet the challenge") if it were tack sharp and there were more negative space to one side of the foot/shoe.