ANSWER:
There is no problem in making Duaa against a sorcerer. However, no one has the ability to know the unseen except Allah azza wa Jal and anyone who claims to know
You must maintain your daily adhkar of morning and evening, before going to bed, after every fard prayer, while entering the washroom, while going out of the house, before eating etc and this will act as a shield against everything evil with the Mercy of Allah. You will find these duas in a booklet called ‘Hisnul Muslim’ or ‘Fortress of the Muslim.’