Stop *****ing my airtime!!

I'd really like for Vodacom to stop *****ing my airtime. I usually buy airtime every day or every second day. With some of my airtime I buy data but I always make sure that there is airtime for me to make phonecalls. However, every single time when I buy airtime, before I can use it, it's gone!! Literally, a half hour round an hour after I recharge it's gone. When i buy airtime at night, my data is switched off until the morning, and when I wake up I will have my entire data bundle left and not a single cent of airtime!! I will use the internet yes, but that's what my data bundle is for! And I always have at least 1 gig of data on my phone at any given time. So without me making even a single damn phone call, my airtime always just disappears. I have a job where I'm constantly on the road so I can't be without airtime, but I am always without airtime! Vodacom... Please guys. Address this and refund my back airtime that keeps on vanishing into thin air.