Insulting customers in public viewing

I took out a Black Friday contract online which was delivered on Friday 01.12.2017. I needed to buy a nano-sim therefore went to Vodacom Data Store TygerValley to get the sim Sunday 03.12.2017. I paid R63.00 for the new sim and was told it would be activated in 24hours. The guy assisting me was very rude but I thought I will just overlook it. However buy Monday evening the sim was not yet activated. I phoned vodacom online who told me that they have not received a request to activate the sim. I therefore went back to the store and was told by the guy who assisted me the sunday afternoon in the presence of all his customers that he tried phoning me the morning as my account is overdue. Since it was after hours and I needed the sim to be activated I paid R501.00 that according to him was overdue. I have subsequently checked my bank statement and the debit order was processed to Vodacom on 27.11.2017 and I've phone their accounts department who confirmed that my account is up to date. They cannot clarify why I was told my account is overdue and my sim-swop couldnt be processed. I understand admin issues can sometimes arise but telling a customer loud that they are overdue is just not on. I felt insulted especially since I knew my account was up to date. The attitude of the sales guy was totally unacceptable as I even asked him the Sunday if he had a bad day because of the way he treated me and he say "Yes Maam" I'm sure his manager will know exactly who I am referring to.