Zero service from Telkom

End of March I received an incorrect invoice for R13000 rand for my fibre line. I contacted Telkom and they said the invoice was an error, they will correct it. Come mid-April and they disconnect my fibre line due "no" payment. I phoned them and the line got connected again. 12hrs later disconnected again. This time they claim my account was deactivated due non-payment. It took them 4 days and many phone calls to sort this out. the line got connected again and only worked for 12 hours, disconnected again and now their app shows again that I need to pay R13000. They promised to phone me back after I spent an hour on the phone with them today - still waiting. Now I receive an email and they ask me what my account number is - really? So I write them the account number but the email shows undelivered due to full inboxes at Telkom! I can not change the service provider as Telkom is the only provider allowed in our estate!!!