Answer
(Fatwa: 2111/1941=D/1429)
If, by the word saya, you mean the effects of jinn, then it is right that jinn and magic have such effects. However, believing any place or person to be affected by it will be acceptable only when any pious and talented Aamil confirms it. Otherwise, as an inexperienced doctor sometimes misdiagnoses a patient, in the same way an ignorant or unaware aamil misinforms about the effects which can not be trusted, since it leads to superstition and other evils.
The verses of the Holy Quran have shifa, so reciting them or writing them as taweez for getting cure is lawful.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband