They are adjustable. The aren't slotted, but the toe is adjusted by loosening the four gold nut and bolt sets and you can move the stub to suit. Chances are you lost a shim on the camber, or they are simply not tight enough and shifted. The bolts, well nuts, are locking so they won't "fall out" bit they are pretty torque specific.
Now all that said I understand that had a bad batch some time ago, I don't have the specifics but remember there being some warranty replacements none the less if you didn't wheel hard enough to bend it, the frame isn't flexing out of spec ( which can happen when not strong enough, of course if there is the receiver tube installed in each side linking them then it won't happen) chances are its just came undone, line it up and tighelten them back up.