High caffeine espresso

I recently ordered a high-caffeine espresso and noticed something odd. On the box, it says there’s 200 mg of caffeine per 2-gram serving, but when I opened it, the sachets inside say 400 mg per sachet. Has anyone else bought this? I’m trying to figure out which one is accurate because this feels like a huge discrepancy.

I have an exam starting tomorrow and lasting for the next twelve to thirteen days, and I’m only half prepared. So, I plan on using this to keep myself focused and alert. That said, I obviously don’t plan on using this in the long term. Just wanted to see if anyone else noticed this or knows what’s true!