Dropped Calls / Insufficient Bandwidth on Data Line

I've called Vodacom many times in the last 2 months to report dropped calls, calls going straight to voice mail. Limited bandwidth or intermittent connectivity on my data line. Today again, I called Vodacom. The call kept dropping and Refilwe tried calling me back, only to have the call dropped or to get a 'missed call'. I eventually got through only to be told by the consultant NO calls have EVER been logged - she couldn't even trace my Hellopeter.com comments! I'm about to pull my hair out. Kindly contact me urgently as I would like to cancel my data contract as I do online studies and can not make one conference call without being cut off. This is affecting my studies and I can't carry on like this. I would like to cancel so that I can get a Telkom Fibre line which is reliable in this area.