Airtime disappear

This morning I got my R200 monthly airtime and data. Then after a few hours after making NO calls at all vodacom said I ran out of data and airtime and that I must recharge. I havent even use my 2Gb data bundle yet! So now I had to load airtime to be able to use my phone. I pay my contract every month, and this is the service vodacom provides. I am a very unhappy vodacom customer today and is seriously considering to move to a different service provider. I pay a lot of money every month. And today I had to load prepaid to be able to use my phone. Where is my monthly airtime and 2Gb data bundle?!?