CELL C: DATA *******!!!

I recently renewed my Cell C data contract and have now cancelled my contract. I was sold an all day data package of 15GB at R150 per month, the previous package was a 20GB (5GB day, and 15GB night owl data). Since moving to the all day 15 GB package, it felt like my data was just disappearing. I hardly used my router except for some time in the morning and in the evening after work, and all of this time never amount to more than 2 hours without any downloading, just whatsapp and other social media, however after a couple of days I would notice that the data usage would be in excess of 5GB???? When I asked for a detailed report on what could be using up so much of my data, they only say internet, not specifics about the apps and then on top of that they would be billing me dubious amounts. So think twice before getting a data contract with Cell C. It's a ****, they are data *******!!!!