Why do you no longer have the warranty?
Your statement implies that you once had it and now you don't. That's not how the mtp warranty works. The lifetime warranty covers manufacturing defects. You could have it replaced in case of an electrical or other manufacturing defect a hundred times and it would still be there for you.
If you did something stupid and are responsible for breaking your own earphones then you should have mentioned this rather than saying that they "stopped working". You only get one replacement for being dumb (which is still better than any other earphone warranty, given that this stupid act can happen 5 years or 7 years or however long after you bought them). After the one-time you-were-dumb replacement, the lifetime warranty against manufacturing defects is still in place. So, the only reason you wouldn't "have warranty" after having previously had it is if you did something dumb to break your earphones twice and Monster Cable called you on it.
Unless there's something you haven't told us, I suppose.