What is the ruling on retrieving money with the help of someone who deals with jinn, or on committing suicide, to solve a serious financial problem?

Do not despair of Allah's mercy, and have a good opinion of Him, and turn to Him in all that concerns you, for Allah answers the distressed and removes afflictions. Suicide is a grave and major crime, committed by those who despair of Allah's mercy, and it leads to painful torment in the Fire. It is not permissible to seek the help of jinn to know the unseen or to find the lost and the like, for this is polytheism or a means to it. Instead, you must rely on Allah and turn to Him, for trials may be a path to repentance and return to Allah.