An alternate email address is not the same as a rescue email address. If you don't have a rescue email address set up then go to Express Lane and select 'iTunes' from the list of 'products' in the middle of the screen.
Then select 'iTunes Store', and on the next screen select 'Account Management'
Next choose 'iTunes Store Account Security' and fill in that you'd like your security questions/answers reset.
You should get an email reply within, I think, about 24 to 48 hours (and check your Spam folder as well as your Inbox)