Q: Iphone5, IOS 9.3.3 Hotspot problem

Hi,

I use Iphone5, IOS 9.3.3, I activated Hotspot for the first time after latest IOS update.
It started well, I had normal access to functions menu but I would not connect with host. I gave up. later I noticed the Hotspot little icon was on and decided to stop Hotspot function but impossible. When I enter menu Mobile, the Hotspot menu activates automatically and changes the item label to "Set-up Personal HotSpot  and when I click it open a popup saying " Set-up Personal Hotspot : to enable Personal Hotspot on this account , contact carrier".

I dont' want to activate nothing, I want to stop this function. IMPOSSIBLE. I rebooted phone, start ans stopped any communication options (wifi, data, Bluetooth..). STUCK
Please advise how set to non active HOTSPOT
Thanks