Poor customer service and arrogant cashier

So i got to the till and was assisted by a lady called Bridget Mafere in Boxer(Brits),she had an unpleasant face as i approached her,with her not saying a single word to me i gave her the products i was buying,and asked for R350 cash back,after tilling the stuff she asked the till packer what amount i requested,and her how was she supposed to hear me when i'm speaking like i don't want to,i was like "HEBANNA,i said whatever it is i wanted because i saw that you were not in a good space and i thought i should let you be"she went on to say i have problems,i asked for R350 cash back AGAIN and went on to explained that the reason i'm saying this is because you didn't acknowledge me when i got to the till,you didn't even greet me,she said at Boxer they don't greet people,maybe where i work its emphasized,but with boxer its not a must.i decided to let it go,and told her to give me the money,She gave me R343 cash back and said it my change and its my fault that i made her make that mistake because i talk too much.I would like for boxer to really deal with this lady because she really degraded boxer standards by advising that boxer doesn't emphasize good customer service and she doesn't pay attention to details.now where am i supposed to withdraw the remaining R7 to make it R350 that i initially wanted?