MTN Fixed LTE Data Dissapeared

I recently signed up for two MTN contracts. One cellphone and the other LTE. So far so good until yesterday when to my surprise my data usage didn't make sense. Firstly I was surprised my data (10 GB) which I had recently bought depleted quick. I thought maybe it was my usage somehow. I proceeded bought another 10 GB which also disappeared out my account at the speed of light (less than 2hrs) this time the only devices connected to the Wi-Fi is a cellphone and a gaming console which both weren't consuming a lot because there were no downloads nor streaming. When I contacted MTN they told me that my Playstation consumed 5GB in total within 24hrs. Okay if that's the case. What happened to the other 15GBs because within 24hrs I had bought a total of 20GBs. Where did my DATA Go MTN 🤷🏽♂️