The "subscription" tab that I go to, to try and cancel my premium account keeps telling me that I have to cancel it through itunes, except when I log into my itunes account, the suscription isn't there to cancel. The receipt that was sent to me via email lists a different email of mine for my apple ID, but there's no way I can use that email to log into itunes because it doesn't exist as an apple ID.
That is odd. Have you tried getting in touch with Apple support so that they can take a look behind the scenes for you? You can check Apple's ID support here or check Apple's instructions for canceling.