So dissapointed

Wow what can I say other than Vodacom is such a dissapointment. I upgraded in the beginning of December and took a double deal. Then paid my bill as per the invoice that was send to me. Keep on getting calls and msg saying I am in arreas. I have phoned numerous times and spoke to numerous people each with his own explanation. I am being charged R125 for the extra line. Johan in upgrades says its a glitch on vodacom side Dodo says its on there side it will be rectified. One said it was for December and I informed him the lady who assisted with the upgrade said the upgrade is only active from beginning of January so nou I ask does anyone at Vodacom knows what they are doing. I have been with vodacom for almost 15 years and I always have an issue with Vodacim but they never have to phone for payment. Where do I go from here. I have asked numerous times to speak to a manager but still no help