Poor communication and service

I received a call from Vodacom for an upgrade last week - ie extra data firstly and then minutes. I took the minutes as the telesales person from Vodacom was exceptional and helpful in advising the total costs - which I confirmed a few times during the call and at the end. On receipt of my first invoice - there is a difference to the price settled on - firstly I emailed the query to Vodacom support and received no response after 48hrs. I called in and received a reference - being told it was being investigated and without any correspondence on outcome - thereafter received an SMS stating it was CLOSED. Calling in again - I have been advised it is still being investigated..??? , seems internal and external communication at Vodacom are not on the same page, how long does it take to pullout out your recordings off your calls - I have now been told it will be another few days - and whilst talking to the REWARDS DEPARTMENT WHICH I WAS NOT COMMUNICATED ABOUT - my call was cut. Is this the service I can expect in the near future from Vodacom and its supporting staff. Utterly disappointed. I need to rethink was it worth the migration of service providers. I am sure come end of the month a full amount will be debited because it does feel like the snail pace you solve issues is at a premium to justify your poor services. I would have thought there would be more urgency in offering clients quick responses and resolutions to keep them on board.