It's inconsistent whether they charge for a refrigerator for medical reasons of not.
In the way past, it used to be free if you had medications, but then people reported being charged. The reason they were given was that too many people without medical needs were just saying they had needs to avoid paying for a frig. People reported being told that their choice was either to pay the fee or keep their medication at the resort front desk (even if it meant multiple trips each day to the desk to get doses). For a wheile, people were reporting that even if they arranged fro the refrigerator theu the Special Needs Department, they could not get the fee waived.
Recently people have been posting that the fee was waived, so it appears to be swinging back to that. Call ahead like Piglet and docgrumpy said and look for the confirmation sheet to say "For medical reasons" or "No charge". Also make sure your medication is in the original pharmacy bottle with a sticker that indictes it needs refrigeration.