21. When a person has obtained that a loan be guaranteed by the Corporation by a false declaration or fraud, or has used any part of the sums borrowed on the guarantee of the Corporation for purposes other than those for which the loan was granted, or if the amount of the loan exceeds the limits fixed by section 4, or if he is otherwise in default, the Corporation may declare that he has forfeited the benefit of the term granted and exercise the other civil recourses conferred on it by the act and the contractual documents.