I am evidence that this isn't specifically Truman related. I didn't even go to school there, never applied for school there, and don't even know anyone who went there. I did graduate from from a public Missouri university one year ago though so it's probably a Missouri thing more than a Truman thing. Didn't answer, no message.
The prefix is primarily used by Truman State University and a number of TSU/NMSU grads have reported getting calls on other websites. I will report the pattern of calls to the TSU IT department, since there is no answer it may be somehow tied in to computer system. The prefix is also used by some State of Missouri offices in Kirksville. If it's not a TSU number, I may report it to Jeff City!
I think Tel Alumni should know that as I am an alumni, I was forced to go back to school to get a degree for a job that makes some sort of money. Go away, Tel Alumni, unless you'd like to pay for my Master's degree! :)