Reservation Counter – Misleading reservation

I was booking complimentary rooms for Bally's Casino resort in Dover, De. I was told no complimentary rooms were available. I was charged a room rate for two nights. However, when I called to cancel, they were going to charge me a fee for cancelling because i didn't cancel in time. Then I called the casino reservations and complimentary rooms were available. Now I am disputing the charge for a full refund.