Chances are that's just a coincidence. We don't have T-Mobile but still got a couple of calls from these scammers/spammers on our business land-line. These robo-dialers don't need a list of numbers. They can just keep calling one number after another, one digit and one number apart, through land-line numbers and (illegally) cell phone numbers.
We keep getting called by this number (307-316-7516) about consolidating debt. I asked how they got our number, and they said "from Washington DC, they provide us with the tel. Numbers of people in debt." I replied that that was interesting as we do not have any debt, and hung up. Sounds fishy to me!
One customer service call to t-mobile and today 3 calls from strange numbers with no messages. Turns out one is a T-mobile customer feed back number the others are to consolidate my debt, what debt would that be I ask? Why are you selling my number T-mobile, must be time for a new carrier!