active.com UNAUTHORIZED WITHDRAW FROM ACCOUNT Internet

I signed my daughter up through Active.com for a softball clinic with Missouri State University, and of course there was a charge for that (I was aware of that) but not aware that they would feel free to take additional money out later on.  I checked my bank account today and it shows a withdraw pending for $59.95.  I called the bank and have to go there tomorrow and once it clears my account then I can request them to reverse it and pay me bank.  I authorized ONE time and they apparently think that gives them access forever.