Vodacom poor customer service

I have a Smart Data 4GB Line Rental contract with Vodacom. On 7 October 2021 my data was depleted, which I found very odd since my data gets renewed on the 1st of every month. I purchased an additional 1GB data which ran out in 20 minutes. I used the myvodacom app to look at my data usage for 1-7 October 2021 and it was a mere 603.78MB, and on 7 October 2021 it was only 46.62MB. I contacted Vodacom Customer Service (ref ***) and explained the problem. The feedback that I got was that the reflected data usage is accurate. They suggest that I use the myvodacom app to track my data usage. I used the app and I only used 603.78MB of data from 1-7 October 2021. Where is the rest of my monthly 4GB data and the additional 1GB of data that I bought? Vodacom is unable, or unwilling, to help me and to explain what happened to my data.