icloud calendar not updating alerts when changed on mac osx mavericks

I mainly use Calendar.app at my work computer, MacbookPro 2.3 gHz Intel quad-core i7, 8 GB RAM, OS X 10.9.4. I make most changes to appointments there. But iCloud is not updating when I change alerts. I have removed a number of alerts on my mac, but they continue to appear on my iPad 2 and iPhone 4. Does anyone know a way to fix this? All of my calendars are on iCloud, so I don't want to replace my data with the iCloud copy. I want what I see and have pushed to my devices the data that I see on my mac. Thanks for any help.