Where the delegating party is a creditor of the delegatee, its claim is extinguished only by the performance of the delegatee’s obligation to the delegatee and in due proportion. The assignment or attachment of the delegator’s claim shall only be effective subject to the same limitations. However, if the delegatee has released the delegator, the delegatee is itself released with regard to the delegator, up to the amount of its commitment to the delegatee.