Bad customer service

On the 3rd of january 2018 I went to pay my grandmothers dstv account she gave me a slip to make a payment with when I got at till the lady who assisted me by the name of thandi was So rude to me I gave her the slip and money to make a payment she said to me that they slip is unclear what am I expecting her to do with it since its unclear she was very impatient with me she told the other cashier to assist me because she doesn't see the reference I told her that since u can't see the reference let me call it for you than you punch it on the system ,she than told the other cashier to deal with me because the is nothing she can do than the other cashier assisted me in a polite manner saying that I should bring a proper slip because the one I have didn't have a clear reference. The lady called thandi at pep store pimville square Soweto was rude and never gave me proper customers service.