Am I obligated to pay the cost of replacing the mobile screen after I refused to complete the repair due to another problem, but the worker did not listen and installed the screen?

Resolving disputes falls within the purview of the judiciary, as it is best equipped to hear from all parties to a conflict and ascertain the truth of claims and evidence. A mufti, on the other hand, hears only from one party and cannot issue an accurate ruling. What has been mentioned here is in a general sense and for guidance. If the worker was not authorized to repair the phone, then he is not entitled to payment, and his work is considered a voluntary act. The woman may, out of kindness, give him the cost of the repair as charity.