The problem is we don't know the full story.
Did the OP walk into the store and say "I want to use my phone as a hotspot while I'm traveling?"
CSR: "Sorry sir, you're on a unlimited data plan and that option isn't available to you."
OP: "But my friend uses his phone as a hotspot. How come he is able?"
CSR: "Because he is on a paid data plan, not an unlimited plan."
OP: "OK, give me a plan so I can use my phone as a hotspot."
Where's the manipulation in that conversation? Did the OP ask if there were other options? Who knows? There is almost always two sides to a story.