Data usage enquiries

This is the most disgusting network or service provider I had to deal with.Loaded data last night within 5 minutes by only using WhatsApp then I have already used 50% of my data after loading one gig and by just replying to a text message on WhatsApp then after about 15 minutes it says 80% of my dads has been used.I called customer care today they telling me that google app is using lot of data😳how can that app use lot of data where’s I did not even search anything am not using it .Can someone from Mtn call me because this is ridiculous and f&# frustrating and this is not the first time this is happening From you guys.You can not just take out data like that without explaining.Can i please have my data back no one can allow such never we spend money to buy we don’t get them for free so u better sort this out because it’s ******* been quiet for too long now sweeping it under the carpet but I can’t anymore this has been going on for far too long🤬😡