Refusing to swipe my master card debit card

I'm so disappointed with the service i received from Emily and her colleagues... i went there on Saturday (24.10.2015) to buy groceries and was using this my cresta debit card, before they even swipe the card they just told me that they were told not to take any other debit card except for fnb,standard bank,absa and capitec. They only take debit cards from the known banks and they were directed to do so by their manager Glenda. I use this card everywhere.. i swipe this card everywhere where a speed-point is available. Why didn't't they at least try to swipe the card and see if it works or not or they just wanted to be little me and make me feel like i don't have money in front of everyone. I'm sickened by their behaviour and the way those two cashiers were laughing as if i don't have money. I hate spar after this experience and i wont put my foot inside that shop again because i will always be reminded of this horrible experience.