Bad customer service

No man you guys are not serious. I lost my card and emailed you guys to deactivate it and link the new one and you guys did that but when i tried to use my cashback now i was told that I don't have any and when the card department was contacted I was told that someone in Durban used my old card ( the card that you guys claimed you deactivated to activate my new one.). Seriously?? The incompetency?? Wow!! O and that Thabisa lady from The card department was so unhelpful.