What is the ruling on believing a raqi who deals with jinn, and does this fall under the Hadith of the Prophet, may Allah's peace and blessings be upon him, concerning the non-acceptance of prayer for forty days?

Those who deal with jinn should not be sought for healing, nor should they be believed. There is a concern for those who believe them due to the warnings mentioned in the Hadith: "Whoever goes to a diviner and asks him about anything, his prayer will not be accepted for forty days," and "Whoever goes to a diviner or a soothsayer and believes what he says, has disbelieved in what was revealed to Muhammad (peace and blessings be upon him)."