Price difference

I went to Maponya store saw a pair of shoes the other pair had a R220 sticker the one that i had didnt have a sticker i took them went to the till when the cashier scanned the shoes the price was R250 i told him that no its R220 he said no R250 and i said to him let me go get another pair to show that it was R220. When i came back with the same shoe he still denied me to get it on that price i saw, he then called someone i dont know if it was a manager or supervisor who just blunt shook her head, she said if i the one that i had had a sticked she was going to give it to me but the ones that i had ddint have a sticker and there was nobprice sticker at all. I said its fine im leaving them behind she authorised the transaction and left i felt broken i have never experience such in any woolworths shop. Now my son wont have school shoes, im so sad i was not treated fairly