You said you don't threaten a legal response until after months of failing to get resolution. I'm pretty sure that's what's being suggested here too. Don't open with the legal threats, as they can shut down what may have been a much faster and easier customer service resolution.
By GP sure, but the comment I'm responding to is an unequivocal "this is a bad idea". My take is apply common sense and don't make idle threats on the 2nd email or you just look silly, likewise when you get to the stage of few other choices make the threat just once. Then get on with it. :)
