Does a debt cease to be owed if it is repaid to its owner without his knowledge that it is a debt settlement, and what is the ruling on depositing the amount into his bank account or sending it via a quick transfer in the name of another person without disclosing the reason for the transfer, and is it necessary to follow up on the receipt of the amount in the case of a transfer?

The rightful owner must receive his due in full, knowing that this money is his right whether he knows the name of the depositor or not. By doing so, the recipient's obligation is cleared. It is mentioned in Al-Insaf from the Hanbalis that if a person receives a right as a gift or a connection, and does not know its nature, his obligation is not cleared. Moreover, it is not permissible for a Muslim to abandon his brother except for a legitimate Shar'i purpose, such as abandoning a fasiq (transgressor) for his transgression so that he may repent, otherwise it is not allowed. Therefore, it is advisable to greet the companion upon meeting him and deliver his right to him directly. One can choose not to accompany him merely for that reason.