Day light ******* on Data

I have always favored and loved MTN SA network but today I am so disappointed to a point I cant even Express. Bought 2g of whatsapp data around the 24 to 25 to last me for a month and I dont even chat nor check status but now am left with about 200mb, today bought R17 120MB weekly data googled one thing than gone. When I call the service champions am told to check on my phone what's the data usage like really. I wanted to know if they have changed there service rate on data. We cant be on lock down and MTN robbing us. I want my data back. This *******. Am So disappointed.