Vodacom
Charged for service that I have not received

In March 2013 I took out a new contact and changed from a Blackberry to Iphone 500.
A few months later I noticed that I was still charged monthly for the BIS- Blackberry service, which clearly I was not using as I no longer had a blackberry.
I called in, asked for it to be stopped and asked for a refund of the amount that was charged.
Since then ON NUMEROUS TIMES, i have asked for the proof of the refund.
This week I went into the Norwood branch, asked for details which they said they couldn't give as they no longer have access to the accounts.
Yesterday I was told by 4 staff that the onus is on the customer to tell them when upgrading that you no longer require the BIS. They do not automatically stop this service or even mention it.
The way I interpret this is that it is to knowingly upgrade and continue charging for an obsolete service.- and then refuse to give a refund.
I am sure this is happening to thousands of people and it is another way that we are ripped off. The consumer Protection act should be aware of this policy.