Straight Talk complaint: Hotspot not so hot

I bought a $55 service plan from straight talk , whom I’ve been with for 3 years, and bought my first hotspot card 5 days ago from straight talk December 16th of 2021. that came with unlimited high speed data, 15 GB of hotspot data. 4 days later I went to connect my hotspot to my internet TV and my phone courier, straight talk, won’t allow tethering. Never using the hotspot since the purchase they told me I’ve used all my 15 GB of data, but upon checking usage of data through their helpline I only used 3.13 GB of data out of unlimited. How could I have lost all 15 Gb of hotspot data when I never turned any devices on to my hotspot? I think they are fraudulent and that they still your data away from you to make you buy there data add-on cards or their proxies or any of their Internet devices. In my opinion they are thieves and I will never buy another straight talk service plan again in my life.