As Poohnatic said, there is some inconsistency in whether or not WDW will charge you for a refrigerator. I don't think it depends on what medication you have because some people reported getting charged and other people reported getting the charge waived with the same medication!
You might want to try dealing with WDW Resort Special Reservations, rather than CRO:
(407) 939-7807
(407) 939-7670 [TTY]
Special Reservations deal with special needs requests.
WDW used to give free use of a refrigerator to anyone who said they had a medical need for one. From what some people have reported they were told, WDW began charging everyone (medical needs and all) because too many people who did not have a medical need were saying they needed a free refrigerator just to save money. The option that was presented to people if they didn't want to pay was to store the medication in the resort office, even if it meant 3 or 4 trips a day to the office to get doses. Recently, people have been reporting again getting the fee waived for medical reasons, but for a while, no one was reporting any luck(even when they dealt with Special Reservations).