Dangerous experience at Denims SA, Coupled by terrible client service

Dangerous experience in store. The cashier was unprofession, rude! I received no proper help when trying to fit on jeans. And told my sister the lady was actually useless.. Which she was! They were on cellphones & not helping clients! When eventually wr sound our sizes(by ourselves) the cashier asked me why i said the saleslady was useless... And she did not ring our items up but argued with us(I said i mentioned it to my sister not to her..) But she was *********** really. We decided to walk out and leave our 4 items behind. They spoke in a black langauge & the security grabbed my hand and said i want to see ur bag. I showed him my bag. My sister left the shop... He held me in the store.. My sister came back to show we had no items as her bag was so small. It was a ploy to be nasty with us i think. Please management investigate this matter? I have a business & i know whatvthe consequences are if we lose business through bad staff. Thanks Natasha