If you don’t want to answer calls, you can easily block them on your iPhone 5s. Here’s how:

  1. Open the Phone app and tap the “Phone” icon at the bottom of the screen.
  2. Tap “Settings.”
  3. Under “Call Settings,” tap “Blocking.”
  4. To add a number to be blocked, tap “+ Add Number.” Enter the phone number or contact name and press OK. To remove a number from blocking, press - Remove Number.
  5. To change how long calls will be blocked for (in minutes), tap “Duration.” You can also set a time limit for all calls or just specific call types.
  6. To enable or disable call blocking, tap “Enabled” or “Disabled.” ..