Rude and Unprofessional Staff at Retentions Team

I called Vodacom customer retentions today to terminate a sim contract I had. The person assisting me, Serena, was rude and unprofessional throughout our call. There was no courteousness, and when I pointed out to her that she was being rude in how she spoke to me she told me that she told me that customers who cancel contracts end up taking out new contracts and she needs to explain all the options. When I again pointed out that as a long term customer I did not appreciate how she spoke to me, she cut me off and spoke over me. I asked her for a reference number for the call so that I could complain about the service I received, she told me that there isn't one. I reminded her that the work she is doing is essentially customer service, told which she responded that no, she does retentions, there is no customer service with what she does. I found her to be very unprofessional and rude.