Kompakt gives you many ways to block numbers:
You can choose to block all hidden or all unrecognized numbers
You can block individual numbers when you add a number to your blocked list
You can block a number during an incoming call
How to block hidden or unrecognized numbers
You can block all incoming calls and messages from hidden numbers. You can also choose to block all numbers that you don’t recognize, you will only receive calls and messages from numbers in your contacts list.
To block all hidden or unrecognised numbers:
Tap Phone
Tap Recents
Tap App settings icon in the topbar
Tap Call Blocking
Use the Toggle switches to select either Block hidden numbers or Block unrecognised numbers
How to manually add a number to your blocked list
Tap Phone
Tap Recents
Tap App settings icon in the topbar
Tap Call Blocking
Tap Blocked Numbers
Tap Add to blocked or the Plus icon
Enter the number you want to block
Tap Block
How to block a number from an incoming call
When you receive a call from the number you want to block:
Tap the Block icon
Tap Block number
How to unblock numbers on Kompakt
Tap Phone
Tap Contacts
Tap the App settings icon
Tap Call Blocking
Tap Blocked Numbers
Tap the Minus icon for the number you want to unblock