Dec 5 Update 6: I Win
Ok, the battle is over, and I am the victor.
I just got a call from Ken at T-Mobile, basically told me that he understood the situation, and that there had been some 'negative' communications between us. He explained that this had to stop, or we would both be in violation of contract (TOS - spamming or something).
He explained that this other guy had changed his reply to and send addresses to match my address. I don't know why he was able to do this, but I am assuming that T-Mobile will make sure it can't happen any more. This guy has the same last name as me, so it was just a coincidence. However, he explained that it was completely this guy's fault, but nonetheless it had to stop.
I am imagining that they contacted this guy, and he promptly went off telling them that I was harassing him and spamming him with threatening emails

roll

, but I think the important thing is that I won.
Nananana naa naa! You got in trouble! Made you eat your parents!
Thus concludes my epic struggle.