Mommy Freebies

HELP!! I accidentally subscriped to Seventeen Magezine!!?

Ohkay. I was at Wal-Mart and decided to buy seventeen magezine. I decided today to enter The Freebies section. But by accident, I also signed up for a 12 issue subscription. I did not want a subscription yet, and my mommy is gonna FREAK!! Please tell me how to reverse this. I have sent many emails out already today and have gotten no replies. Please help??

its only like 10 or 12 dollars for a year subscription and 17 is a pretty cool magazine so id just tell your mom that ull find the money to pay for it..no big deal