Poor customer service SHOPRITE NONQUBELA

Good day Sir /Madam I am so disappointed at the poor service I received at Shoprite (Nonqubela) Site B , Khayelitsha. Not only did they embarrassed me they did it twice . I received an electronic voucher from FAIR CAPE DAIRIES , when I went to redeem it the 1ST Time the cashier said “ Ayithathi sisi” I left and decided to come back the next morning as I was going to send an email to FAIR CAPE DAIRIES. Mind you I needed the milk , the ques are long and slow .. I came back the next day with the email , the Cashier couldn’t do it , she called the manager .She also said “ Ayenzi” then said the voucher is for yoghurt only . The email clearly states it will be minus on my bill . I am not sure what level of incompetence is at NONQUBELA SHOPRITE , it is rather disappointing and sad that as a customer I left the store twice without being assisted . If the manager didn’t know how to go about , why not call customer service for assistance . It is not the 1st time I get this poor service from that particular store . I was once disrespected by the SECURITY GUARD at the Liquor store , which resulted in me calling the manager in order to get service . THIS IS UNACCEPTABLE !!!!!!!!!