I received a letter from USAA saying that these people would be calling to update my insurance policy. They also listed the number and said that I could call the company directly. So this is a legitimate call
I shall assume that the rest of you reporting USAA are accurate since I received the letter from USAA about PSI but they provided an 800 number, not 210 area code for San Antonio, where USAA has its HQ. I still do not appreciate a hang-up from this number, now up to about four calls over three days.