my headphones dont work?

Buy new ones.

Test the headphones with other audio device -if they work there, then chances are that the audio jack of your device is damaged. If they still do not work and you are sure that the audio jack is clean (clean it first and see if it helps), then you need to ditch those and get yourself something more reputable/durable such as Sennheiser, Shure, Grado, Denon, AKG, Bowers & Wilkins, Bang & Olufsen, Etymotic, Beyerdynamic, Audio-Technica.

Then again, NOTHING is unbreakable, so you NEED to learn to take a GOOD care of your audio gear from now on as well.

Maintenance tips:

Buy yourself a protective carrying case/pouch and put your audio gear in there whenever not in use
Always unplug your listening device whenever NOT in use
Do NOT wrap the cord around ANYTHING, do NOT let the cord become tangled!
Do NOT jerk your head too much while listening to the music
Do NOT pull from the cord, pull from the plug
Do NOT drop your audio device
Do NOT fall asleep with the earbuds on!
Do NOT crank up the volume to the max, this kills especially earbuds VERY fast because small earbuds canNOT tolerate maximum volume!
If using in-ear earbuds, please keep the plugs as clean as possible by using DRY lint-free cloth or DRY Q-tip or swab. Do NOT use any alcohol-based cleaning detergents!