iTunes Store: Purchasing and managing auto-renewing subscriptions.

None if the information found on the "help" for above topic page is what I see as I try to follow the instructions on the page they tell me to go to. I just want to manage how much my credit card gets charged when my kids use this account. So fustrating that Apple will not even let me cancel my account or my credit card. If this is "allowed" nothing on their instructions lines up with what is on the web page meaning I'm constantly dead in the water with trying to get anything done. I think they just baffle people with bull@hit and hope they just give up.