What type of dispute prevents forgiveness for those who are quarreling every Monday and Thursday, and does it include commercial disagreements or not speaking to a friend without any malice or hatred?

The discord that prevents forgiveness is that which leads to enmity and mutual hatred, such as rancor (shahnā'), which is the enmity and hatred that occurs between Muslims not for the sake of religion. As for a mere disagreement without mutual hatred and malice, it does not fall under that. The Sharia has forbidden abandoning friends and refraining from greeting them without a religious reason. However, abandonment for a religious reason is permissible if its effect is hoped for in deterring sinners, innovators, and those who abandon prayer.