What is the ruling of Islamic law on a man whom ruqyah did not benefit, so he resorted to sorcery, claiming that it does no harm unless it causes problems?

Sorcery is a reprehensible act and an act of disbelief (kufr). The failure of a patient to be cured by ruqyah (recitation of Quranic verses and supplications) does not justify resorting to sorcerers, because healing is in the hands of Allah. Legitimate treatment does not guarantee immediate healing; Allah may delay recovery or decree death by the illness. The Prophet, peace and blessings be upon him, forbade seeking treatment through unlawful means. Therefore, a Muslim must be patient and seek reward from Allah, employ permissible means, and believe that the decree of Allah is inevitable.