.What is going on with Vodacom Data? 1 Gig disappears while I am sleeping and nothing is connected.

Come ON VODACOM! How do you manage to take 1GIG data from me while I am sleeping? I bought 1GIG on the app at around 00.30 this morning of 25 July to finish an email. That was it. I finished one online payment and 1 email and when I checked my data before logging off and going to bed is still said 1GIG. So. It still is 25 July and the fact that I did not buy night owl but 1 GIG PER DAY, I had the full expectation of having data at 09.30 this morning when I tried to log in. Nothing. Zero left. How is that possible? How could more than 950MB (give and take whatever you took for the email) just disappear overnight with nothing connected? This is becoming ridiculous. I start to get an idea now why my monthly data just seems to run out like water sometimes and sometimes I have it forever. It is not consistent. What I do know is that this week I have been consistently depleted of validly bought data that I did not use. Please refund my 950 MB. It is not yours. It is mine and I did not use it yet. Now I need to keep buying Flex data to have enough data to buy more data. Totally unacceptable. Vodacom must be trickling millions to themselves this way.