I cannot shutoff my iPhone

No, this is not a joke. This is not an immediate tech support help line, the replies you get are from users such as yourself lending their assistance to a community. If you need immediate help, click contact support in the upper right of the page, this will route you directly to Apple's support page where you can CHAT or CALL and speak to an advisor.

That being said, when you say shut off your phone, what do you mean by that, there could be a number of assumptions that could be made. Are you trying to power the device entirely? Or has it been lost and you are trying to disconnect service. Otherwise check out this page if its the former: https://support.apple.com/en-us/HT201559