2.5GB of data depleted in few minutes without any usage

Considering situation we are in which lockdown, I use mobile data for working from home and all of a sudden almost 2.5 GB of data depleted without me even using my mobile for anything apart from checking watsapp messages. Are you guys serious? I called customer support and they are telling me I have an active connection even though I was connected to my home wifi that time and while talking over the phone I can't use mobile data still it got depleted in few minutes. I had been using afrihost services for a while now and was happy but today its disheartening to not get any support or resolution of my problem even after explaining that I didn't use that data. Mobile data is already too expensive in this country and on top of this data depletion without customer usage is not expected. I hope someone can read this at afrihost.