When is the debtor obligated to discharge the principal financial claim, and what is the appropriate judicial procedure for the defense related to the creditor's retention of the debtor's property?

The debtor is obligated to discharge the principal financial claim if he does not deny the contractual agreement or the validity of the statement of account. As for the defense related to the creditor's retention of the debtor's property, it must be submitted in a separate lawsuit and does not suspend the adjudication of the principal claim, unless there is a close connection that justifies consolidation or suspension.