Unable to cancel Vodacom contract

I have been trying for a long time to cancel my data contract. Or change my Contract sim to prepaid, there is just absolutely no chance of doing this. Customer service put me through to cancellations then the bot says i will receive an sms. Never have i received such sms and cannot get hold of a cancellations consultant. Really people we should make this public and report Vodacom to the ombudsman for *******ly keeping us tied to a cell contract. Its actually *****.