Capgemini Informatica MDM Administrator interview questions

Interview was very easy, talked with hiring manager got offer over the phone on Friday. The recruiter called me on Sat to accept the offer. I asked for written confirmation, he said it will come on Monday. The written offer came in at 9am, as I reviewed the offer, the salary was cut 20% without discussion. Within 1 hour, the recruiter told me that he gave the offer to someone else since I didn't accept the offer within 1 hour. Very unprofessional!