(1) You purchased on the lower end of the quality scale.
(2)Cra.p happens, even to ultra high end, high quality products...sometimes defects don't manifest themselves right away.
I have HD280 Pro's (Silver Edition), they served me well for over a year, but the right channel went dead...why am I not complaining? (1)They had high quality sound and worked perfectly up to that point (2)there's a thing called a warranty that covers them for 2 years.
Try out a little bit better quality headphones from them, next time--the higher end ones have coiled wire instead of spaghetti-like strands...way more durable and less likely to snap.