Vodacom Service is just SHOCKING

I received a call a short while ago from Vodacom indicating I need to sign up to Vodacom insurance as well as Itemised Billing or something. As a mandatory not optional. He claims when they processed my new contract that they forgot to add it in (but it was an option I did not select when taking out the contract).

When initially signing up to the contract there was an option to select if you as a customer would like insurance, I selected not to have insurance, the gent on the line stated that it is mandatory to have insurance. This went on for some time whereby I did not agree and consultant stated its compulsory and what it covers, which is irrelevant as it was never agreed to (hence I did not tick that I want it).

If this is the case then that impacts the monthly premium of the device and contract and it is more than I am willing to pay, as I would have considered this beforehand? The quote I received from VODACOM also has no insurance noted on it?

The gent just put the phone down while we were still talking which is very unprofessional - the number I was contacted on is 0XX *** ***X.

Please can you let me know, why is insurance compulsory? Where was this stated. It seems as if consultants try to force you to just agree so they can push sales.

I have written to customer care but they don't seem bothered as I have gotten no response and I would like to terminate this contract before it starts if this is the case as this was not the agreement when I signed up. If they contact me telephonically please ensure that it is a professional consultant with manners else I would prefer a response in writing. Thanks