No investigation for ludicrous data charge

I received and SMS from Vodacom early in August that there was excessive data usage on one of our business numbers amounting to close to R8,000.00. I promptly phoned them to ask them to investigate because the number in question was not roaming and never used out of bundle data. Each time a low data sms was received an ad-hoc bundle for additional data was purchased. An issue was opened but nothing happened. When I phoned back on the 25th Of August I was informed that the issue was closed without response. I new issue was then opened. When I phoned back in 14 days there was still no investigation. When I phoned again just now, the new issue was closed again without a response. I have asked that the matter be escalated to a manager every time I phoned, but it never happened.<br> <br> It seems impossible to speak to a manager at Vodacom. I need this matter resolved urgently so that we can pay the correct amount but I've been waiting since the 5th of August. In the mean time we run the risk of our account being suspended. This is the worst service I have received from any major local corporation in 20 years of business.