Skullcandy lowrider headphones broke i dont know what is wrong with them?

i was wearing these on my head and my brother caught the wire on his hand and he pulled the wire on accident and now there is no sound coming through the headphones and i cant even take them back to hmv because the guy didn't give me a receipt and i chucked the packaging in the bin and i also took them to a professional fix electrics shop and they said there is no way they could fix them because every part of the headphones are sealed so they cannot take them apart so can anyone tell me what to do with them or what is wrong with them thanks for your help x