Will Not Cancel Contract

Signed a 24 Month Contract for data which expired on 8 January 2018. Written 3 e mails to cancel contract, no response, no e mails, no phone calls, nothing! Can't complain about the service, there is none. Since when does a 24 month contract become an open ended contract, for who's benefit ? What a ripoff. Consumer Protection here I come. If there was a Zero rating, Vodacom will win hands down.