Mr Price Money account is **** meant to squeeze you for moeny

I paid off my account several months ago but continued to be billed. I then went to the store in Northridge mall, filled in a form to cancel everything, including the customer protection plan and 360-degree account holder option. I cancelled everything on 12 September 2020. This month I received another bill for R81. How does the compute with the consumer protection act, Mr Price? Should I involve my lawyer?