Were you charged by Disney because the groceries were delivered and left with Bell Services? Or were you charged because you had Bell Services bring the groceries to your room?
From the official Disney website:
Getting Grocery Orders Delivered to Your Disney Resort Hotel Room
If you have grocery orders delivered to your Disney Resort hotel during your vacation, a $6 fee will be charged to your room account for each order brought to your room by Bell Services or Luggage Assistance. Alternatively, grocery delivery order pickup in the Resort Lobby from Bell Services or Luggage Assistance is available at no charge.
Here is the link (which works even though it will say that it is still loading):
Be our guest! Your wish is our command, as you enjoy this Walt Disney World service.
disneyworld.disney.go.com