Jazakallahu khayran

`Jazakallahu Khayran` is an Arabic term and Islamic expression of gratitude meaning `May Allah reward you for the good.` Although the common Arabic word for `thanks` is Shukran, `jazakallahu khayran` is used by Muslims instead in belief that a one cannot repay a person enough, and that Allah is able to reward the person best.

Calling upon other than Allah is Shirk

It is an act of shirk  (associating others with Allah) and a major sin to call upon anyone in the Unseen — a dead person, angel, devil or jinn — for help or intercession. 

The purpose of Mankind, the sole reason behind our creation, is to worship Allah Alone: "And I created not the Jinns and men except that they should worship Me (Alone)." [51: 56]

Worship has been defined by Ibn Taymiyyah as being: "a term which comprises everything that Allah (s.w.t) loves and approves of from the apparent and hidden sayings and deeds."