Mousesavers.com is all about Disney. If you call Disney's customer service it often depends on who you get. You could call one time and they tell you nothing. Call back and get someone different and they might be likely to let you in on deals.
I have been to Disney a few times but I wouldn't by any stretch say I'm an expert. Some people dedicate a lot of time to finding discounts. Keep looking and I'm sure you will find something.