Why do I need a Telkom number to cancel a Fibre contract???

Dear Telkom I went to one of your stores to upgrade a fibre contract. The consultant told me to call 10210 using a Telkom sim card. I told her that I do not have one. She said she can get me a prepaid sim card for me to make the call. How absurd! So you only do business with people with Telkom numbers! Well, after this I decided to actually cancel my contract as I was not prepared to get a sim card just to communicate with Telkom. Guess what??? I still need to have a Telkom number in order to call 10210!!!! I went to your website with the hope of finding a "contact us" and would get an email to communicate my wish to cancel the contract. Unfortunately "Thuso" was not helpful. How does a non-Telkom numbered client cancel a contract?