No response from cancellations department

I have filled in a form for a cancellation of a service, this I did on the 2nd of January 2018, and according to Telkom it takes 21 working days for them to respond. There is no way that I can contact them telephonicly to follow up on the progress, and this is so frustrating. And trying to send a mail, it either gets returned that their mailbox is full, or the mail adres is wrong!