VODACOM DISAPPEARING DATA

I have had a monthly 10GiG data contract on a router for the past 4 years and have never run out of data, however, all of a sudden today (26 Sept 2021) the data is all used up! The data useage on my laptop indated 8.24GIG used in the last 30 days. When I called the call centre after getting through to an agent my call was cut off. I called again and spoke to another agent and was told that neither TOBY (virtual assistant) nor the agent could not tell me what had happened to the data. That is not good enough! At the very leasst I expect VODACOM to give me a printout showing data useage. Why did my computer indicate 8.24GIG whereas VODACOM claim that all 10GIG were used? I need answers!!