Does the condition of prohibiting abuse of the company or its employees, which stipulates the closure of the account and the non-refund of amounts due to the abuser, constitute a violation of Islamic law? What is the ruling on guiding others to contract with this company given the existence of this condition?

The first condition regarding refraining from verbal or behavioral abuse is valid and permissible. A Muslim is obligated to abide by this even without such a condition, and the condition further emphasizes it. As for the second condition concerning the non-repayment of dues, it is void, and it is impermissible to seize people's money unjustly. This void condition does not prevent contracting with them, and one must refrain from what they stipulated regarding avoiding abuse. If abuse occurs, they do not have the right to seize a person's dues, for loyalty belongs to the one who freed, and every condition not found in the Book of Allah is void.