Can't cancel landline & NO customer service

You can't reach a human being at Telkom for customer service. I tried calling several times in early January and ended up using the self help option online to cancel my home landline, expecting it to be finalised by end February latest considering the required calendars month notice. To date the landline hasn't been cancelled and I have receive a March bill. I do not wish to pay for a service that I have cancelled and hope to have this sorted before the end of March 2020.