Bad service at APM Cape Town Station

I bought APM bus tickets from Computicket when I went to return the tickets at their Cape Town offices I was helped by Ashwin he told me that they do not do refunds they give you a voucher which was fine because I was no longer going becuase I have to go to the funeral I asked him if I can use the viucher for someone who wants to buy tickets he did not explain to me but shouted at me that he will not allow that, is there a way they can communicate to people besides shouting and laughing at people