Strange SAT charges

<p>Recently I got my credit card statement from April and I am very confused. My statement shows a $25.00 charge from the College Board on 4/24 (Regular Deadline, Math Level 2) and a credit of $17.00 on the same day. The difference of $8.00 is the same as the per test registration and the $17.00 is the same as the basic registration fee. Is it possible that the College Board is refunding my $17.00 fee because I took an SATII in march or is something else going on? It still seems like my registration is correct, does anyone have an explanation?</p>