What is the religious and customary ruling regarding a long-term financial dispute between two partners over a medical clinic, especially after one of the devices was stolen, and one of the partners claims that the other stole the device and is damaging his reputation?

The question includes several matters: going to a sorcerer is forbidden and one must repent from it. As for the partnership, it involved a business partnership about which there is disagreement, and those who permit it believe that the matter is based on the agreed-upon division of profit and loss. Your uncle is a partner in profit and loss according to the agreement, and he is not allowed to demand more than that unless he had truly withdrawn before the theft. Your telling him to pay an increase in capital means that you owe the company a debt that will be added during the dissolution. The fact that your uncle built his wealth from cigarettes does not absolve you of your obligations. Estrangement between you two is not permissible; communication and forgiveness are obligatory.