Tuesday special chicken that flew away

I saw this great special offer on Facebook for the Tuesday special of 5 pieces of chicken and 5 zinger wings for only R 65 . Great special or so I thought until I reached the Stellenbosch branch at Simonsrust . I was told that the special was not available on the last Tuesday of the month , I did not believe this as I previously visited that branch only to be told they do not have the bucket for 1 anymore . I travelled down to the Dorp street branch also to be told that the special is not in the cashier register today . Please explain to me how it is possible that my money is good enough to support KFC on a Tuesday for the special but when it comes to month end the special does not exist and the price is normal seeing that most people have received their monthly wages .Please explain !!!!