I took the SAT's with the wrong last name

notypical
Sat, 06 Dec 2014 11:28:56 +0000

I took the sat test in October 11 and everything went normally. Neither I nor the proctor noticed there was a letter missing from my last name. I went to get tested again today and the proctor didn’t let me in because there was a letter missing. Does that mean that my previous score wont be counted? And can i get a refund or register for another test for free because they didn’t let me in? I need answers asap. I’m panicking because people have told me they might cancel my previous score or send the wrong name to universities because of the missing letter.