My account changed from voice to data top up

I have been contacting vodacom for the past 4 weeks and my query has not been sorted. It is frustrating that for the 4 weeks am not able to make calls because my contract was migrated to data. This is my primary number and yet the various call agents don't take this seriously. I have even written to twitter but the useless agents could not even return my calls. I need urgent assistance today!!!!!