I applied for a opportunity and less than 24 hours...

I applied for a opportunity and less than 24 hours the Human Resource contacted me via email for a phone interview. I provide the the time and the day which I am available for a phone interview. I recieved an email a few hours before the phone interview that hiring manager has changed the requirements for existing opptunilthly and the Human Resource will connect me via email . The thing is the HR never contacted me and these changes never reflected on the exiting opportunity on the indeed.com job listing
The conclusion is that the hiring management are can not handle the change and make their mind.