refuse to exchange

They refuse to exchange the garment with the price on it while the head office confirm that they can exchange anything with a tag on even there is no slip we even call the head office number with our airtime.At the same time they do the exchange if you not an black without asking any questions.The incident happen on the 31/12/2015 the time was around 11:50 am.I have also experience the same treatment happen but was not me.While the woolworths policy state they can exchange anything without a slip but when the goods on sales you will receive it on the sale price but not state that you cannot loose your slip if the price is more than R500.00 and above