Xaverian College acceptance letter

yesterday, I received a letter from Xaverian College essentially saying that they have accepted me. I'm not complaining, it's just my head of year told us we would be getting these things in March, so I'm a bit confused. another thing is, I asked my friend whose grades are very high and she said she got no letter. we both go to the same school and its not a school partnered with Xaverian, nor are we Catholic. I don't believe I should have got this letter and a part of me feels that this is an elaborate prank haha, so I was just wondering if.my HOY was wrong abt it coming in March