Discovery Bank is uncontactable

The bank is uncontactable. I have spent 4 months trying to close my account. I now live in New Zealand and want to close an account I do not use. I have spent over R2000 in international call charges on hold waiting for the call centre to answer. All calls have been dropped after 30min. There is no e-mail contact detail listed in the App or online. I have rep**** to every email address discovery bank has ever sent me correspondence from. No replies except for some auto-responses saying the mail account used is not monitored please call the contact centre. I continue to be billed fees for an account I cannot close.