Sorry but what you're saying is that you think one of us deliberately and knowingly signed on in the night owl period to make use of the line. We have uncapped ADSL lines - why on earth would we manually switch over to the 3G and download Gigs of data through that instead?! The only time the line would have switched over automatically was when our Telkom lines all went down (which, as I said, was 20 minutes in Feb). Perhaps you'd like to come and examine our network configuration since you obviously don't believe me.
Since Vodacom clearly didn't come and sit at a computer on our network and download the stuff for us, the only feasible explanation is that there is a glitch in your billing/log system.
Since it appears we have no way of proving this to you and you apparently don't provide logs for us to check what you're telling us, we'll just have to give up and let ourselves be shafted. Or see you in court. Whatever. Like I said, this sucks.