Cancelling ADSL Line is Challenging

I'm unable to cancel my ADSL line online as required by Telkom. The Telkom site has an error "an unexpected error occurred while retrieving customer details. Please try again later" I have been receving this message for a week. I called the call centre who advised they will e- mail the cancellations department and give me a reference. I requested a copy of the e-mail or proof of cancellation. I was advised that they are unable to e-mail me proof of cancellation. All I require is proof so that Telkom cant turn around tomorrow and say I didnt cancel my line and continue billing me. The above reason is one of many reasons I will never deal with Telkom again.