Data ****

My 10GB data was loaded on my router on the 01-09-2019. I never stream anything. I only use it to chat but then I was told on the 10-09-2019 that I have 0 MB, HOW???????? went to the store and they called the customer service. The consultant she has emailed me the invoice or whatever it is that shows how much data I used and when. I am still waiting for that email even now. 2 of my colleagues are also having the same problem. We cant be paying for such service honestly. During the day I use my workplace wifi. I am so ****ed its not even funny