BILLED INCORRECTLY FOR MONTHS

I upgraded my Blackberry Bold to a LG3 in February. On 4 March someone at the Cresta Vodacom store went and activated BIS on my contract although I did ask them to cancel it when I upgraded. I have now been invoiced for 6 months for a service that I asked to be cancelled and that was of no use to me. Will think twice in future upgrading with Vodacom. Bad service costing customer unnecessary money.