I went back to the Chase website to read the rules again, just to make sure they're actually refundable.
Click on 'Managing Rewards Balance' and in the drop down menu select 'View Terms and Conditions'. Scroll down to 'Redemption of Disney Reward Dollars' It says this:
Disney products and merchandise acquired through redemption of Disney Dream
Reward DollarsSM using a Disney RewardsSM Card
can be returned, subject to return policies, that may vary based on the retail location, at designated point of sale locations, and the Disney Dream Reward DollarsSM originally redeemed for such returned products and merchandise
can be restored back to the Disney RewardsSM Card provided that you have the original receipt for the redemption and a valid Disney RewardsSM Card. You agree that you are responsible for checking in advance (i) whether a specific retail point of sale location will accept the Disney RewardsSM Card, (ii) as to the Disney products and merchandise that the Disney Dream Reward DollarsSM can be redeemed for through use of the Disney RewardsSM Card, and (iii) as to the return privileges at specific retail point of sale locations and for specific products and merchandise.
Even the Disney Guest Services person said they were refundable, she just wasn't sure of the proceedure. She told me she would try to find out and get back to me next week. We'll see.