Bad Management branch Malmesbury

Good day I have an account with this retail store but got in arrears because I was unemployed but started working again this year. The manager of the store in Malmesbury Western Cape phoned me during my working hours so I didn't pick up because I don't work with my phone. Then I phoned Head Office telling them that the manager sends his staff everyday to my workplace to harass me about a payment of which I told them that I don't have money right now and that I cannot afford the amount that the manager is forcing me to pay. Yesterday the 1st of February he came to my work again and was forcing me again about the payment of which I told him again that I don't have money and that head office phoned me and said that he will phone me and not come to my work again. He was so aggorant and rude that my supervisor had to ask him to leave the store. He was so rude with her also he told her that he will come to store again.... What can I do or where can I report him??