Vodacom not cancelling contract after 2 requests

In January 2018 I requested that my contract with Vodacom be cancelled by emailing their cancellation department as required. In April 2018 I realised that it has not been cancelled yet, so I re-requested the cancellation. This has also not happened. The monthly fee is not much (R76), but adding this up over 2 years of Vodacom not cancelling my contract, it comes to a substantial amount. Can someone please contact me and resolve this ?