Lightning Cables Poor Design and Quality?

To charge my iPad 2 and iPhone5 I have purchased 4 extra OEM lightning USB cables 1 each for my car stereo, home, office and studio plus keeping the original for my laptop case. I like the small foot print of the newer cable, but already 2 are misshapen and 2 have split the outermost insulation near the lightening/iPhone end. So, Ive had to wrap with electrical tape over the frayed outside coating near the lightening end.

Anyone having the same experience?

Im surprised at this since my cable use is spread over 6 different cables so none gets that heavy of use. I've never had cables for past devices such as 2nd Gen iPod, Samsung Blade, Palm Treo, Palm Pre, or Samsung Epic ever wear out after years of use. Even my 5 different MacBook pro charger cables never wore out out in just a matter of months.

Anyone, are these cables under warranty? I tossed the original boxes.

thanks all