Contract for the provision of medical and hospital services with an arbitration clause. Protest of a negotiable instrument without submission of the matter to arbitration. Failure to invoke the objection based on an arbitration agreement precludes dismissal of the case without adjudication on the merits. On the merits, the unenforceability of the instrument and the impossibility of protest were upheld on the grounds that the amount had not been determined in arbitration proceedings: