Vodacom are *******!!!

As at 30th november i had 60 voice minutes remaining and about 240mb on my account. According to my contract these are to be carried over to December. Today being the 1st of December only 9 min and 101mb were carried over. This is not the first time this has happened. Also when data or minutes are carried over vodacom uses the current months allocation first thus by the end of that month the amount that was rolled over gets forfeit. What a load of rubish is this.? I want an explanation from vodacom for robbing me of my data /minutes and replacing it back into my account.