For proper lager yeast you want temps even lower, 9C-14C.
If you used the yeast that came with a can of extract (coopers maybe?) then it will most likely be ale yeast. Even if the can says "Lager".
Ferment temps kept low will give a cleaner, fresher taste. (well im guessing thats what your after, some people arnt).
Yeast creates byproducts at all temps while fermenting, they can change a beers flavour dramatically. If you ferment at the temp suited to the yeast you will get less weird/funky flavours.
Back when I was home brewing weekly, I found that once I got a temperature controller for my fridge, all my beers started tasting a lot better. Never threw a batch out after that.
Most of the companies that do wort-extract-cans think the common person cant control their brewing temps, so they go ahead and say that you can brew between ridiculous temps (ie 21-27C), of course anyone can do that, and of course there beer wont taste as good. (Unless using belgian or other specialty beer yeast, wont go there now).
I think they do it so people go out, buy the whole kit, get home make beer, then it tastes like its not worth the effort. But at least they've sold you nearly $150 worth of shit.
They create their 'own' yeast packs too, mainly containing ale yeast, but to trick a certain person they put a small amount of lager yeast in there too. Hoping its enough to get a 'lager' taste without putting too much in to get weird tasting byproducts of high temp fermentation.
Not long after I got my temp controlled fridge I started using separate yeasts, threw the ones with the can out.