Am I Taking Someone Else's Spot(s)?

I declined UT’s offer of admission in mid-December, but am still receiving some admitted student mail, the most recent (a few days ago) being a notification that I was selected to receive the Presidential Achievement Scholarship. I already contacted the university a month or so ago to see why I’m still getting these letters, but they haven’t replied. I’m worried that I’m taking up other students’ spots for scholarships like these who will actually attend in the fall, especially the more competitive/exclusive scholarships. Does anyone know whether or not I’m actually taking up space?