Not a tire rotation or balancing issue what so ever.
That being said, that tire was pooched the day they did your rotation. I would start by putting some fresh rubber on the car, all around, then I would get a full 4 wheel alignment and go from there.
Now if you think I'm full of shit and just taking the dealers side, I'm not, they should have told you your tire/tires were finished, and if u post up your pre alignment specs, ill tell you exactly what's wrong, why this happen and what needs to be adjusted to achieve a good alignment. And if this happen to one tire, maybe the one tire was faulty but I highly doubt it by the picture that was displayed in your post.
And to everyone who thinks tires are covered under bumper to bumper, they are not.... they are only covered if u purchase the tire road hazard extended warranty (might not be exactly what it's called) when you purchase the vehicle new I believe (In Canada, not sure about US). Other then that sorry your out of luck. If u get tires covered at your dealer without tire protection warranty, keep going there they have a great service manager lol.
Eric Carrier, proud GM Technician for over 6yrs.
2013 Cadillac ATS, Black, 2.0L Turbo, Luxury package, 20" Strada's, Pirelli Pzeros, 5% tint.
2010 Camaro 2SS Black, L99, SLP headers, GMPP axle back, K&N CAI, JRE tune, 22" Boss 337's, Nitto Invos 5% tint.
2011 Z06 Corvette Black, LS7, Borla Cat Back, 5% tint.