How to set up a mobile phone to intercept harassing calls from all strange numbers?

You need to use the "initial number matching" function, such as filtering out the area numbers starting with 0 and setting up the process:

Tool: iPhone 8

Operating system: iOS 14.4. 1.

First turn on the phone to dial, click "Options" in the upper right corner, and click "Harassment Interception" in the pop-up menu.

Second, click "Interception Rules" at the bottom.

3. After entering the interception rules, click "Blacklist".

4. Click "Add" at the bottom and click "First Number Matching" in the pop-up menu.

5. Fill in the number "0" in the input field, and then click OK.

6. After the segment settings are matched, incoming calls and text messages of all numbers in the segment will be automatically rejected.