What is the ruling on buying materials (baby wipes, baby milk, cosmetics, perfumes, accessories) from a person who exploits his insurance card in cooperation with a doctor and a pharmacy to convert expensive medicinal prescriptions into these materials and trade in them?

If you know that the money in someone's possession came as a result of forgery and lies, then it is not permissible for you to deal with it, and you must advise him and remind him of Allah. The usurped money of the oppressed is not permissible to take. However, if the source of the money is unknown, or if its owner is known to have unlawful elements in his wealth, then you may refrain from dealing with him out of piety. There is no doubt in dealing with someone whose financial situation is unknown.