Receiving your iPhone calls on your iPad or Mac after upgrading to iOS 8 and Yosemite. Here are steps to prevent iPhone calls getting transferred to iPad and Mac
Disable iPhone Cellular calls on iPad
Step 1: Access the home screen on your iPad.
Step 2: Navigate to Settings icon on iPad home screen.
Step 3: In the IPad settings screen, scroll down to FacetTime option
Step 4: Make sure to turn Off iPhone Cellular Calls
Disable iPhone Cellular calls on Mac
Step 1: Launch FaceTime on your Mac.
Step 2: Click FaceTime menu option and select Preferences from drop down list.
Step 3: Navigate to iPhone Cellular Calls section and un mark the check box.
By this way, you can prevent cellular calls received on iPad and Mac