All of these things with strings are cheap-shots, the wires in the strings break way too damn easily ._. Switch to this : GG SOLACE-AIR (or any type of bluetooth headphone, though I recommend this one c: ) These are WIRELESS headphones that use Bluetooth, thus, no strings = can't break
Headphones and earphones are not the same thing, do not use the terms interchangeably!
Also yeah, stop getting cheap ones. Plus what you say is treating them normally might not be treating them well. Rolling the wires up and shoving them in a bag or pocket is a good way to deteriorate the wires quickly, especially if you roll them with sharp bends.
Btw what does "normally" mean in your book? Wrapping them around your MP3 player? Because that IS mistreatment. Go and get yourself a decent pair of headphones or IEMs (honestly, earbuds suck) and put them in a pouch (like this one for IEMs [link]). They'll definitely last much longer.
Unfotrunately, your five-dollar earbuds are breaking because they are five-dollar earbuds. You tend to get what you pay for when it comes to headphones. Even Skullcandy has a really good brand (Skullcrushers) that's worth the money.
Stop wrapping the cord of your earbuds. I volunteered as an audio tech for a couple of years and wrapping electronic cords the way most people wrap them is a fantastic way to destroy the wires inside. I know it's a total pain in the ass to untangle them, but you're seriously better off just putting your earbuds away without wrapping them. There's very fine wires inside the cord that connects to the L/R earbud and whenever you wrap the cords you're putting lateral strain on them until they eventually break away. This is why a lot of people have earbuds/headphones that only work in one ear, too.