Data run out within 5minutes

For the past 3 days my I have bought data and it disappears within 5 minutes, I have bought almost 4gigs of data. I was refunded R35 for 1 purchase and told that there is nothing else they can do when calling the call center. The call center says that I have app running in the background, and there is nothing running in my background as all my apps are wifi only restricted. When i ask to speak with a manager or TL there is no one to take the call or they are "off duty".

I want my data back Vodacom, do better