Useless SA Post Office

I have been trying to reach Brackenfell Post Office over the last few weeks. The call goes to a linked phone but no answer. I then tried the National nr only to be kept in a que for 10 minutes. I then sent an email to customer services requesting a form in order to cancel my post box. No response from that side. I cannot visit Brackenfell as I now live 185km away. What does one do?