The call blocking feature on Oppo phones is inherently available on the device without requiring any third-party applications. You can easily add anyone who harasses you to the blacklist so they cannot call you anymore. Follow the steps below to add a number to the block list on your Oppo phone. If you are using Viettel network and not an Oppo phone, apply the steps to block Viettel calls.
Blocking Calls on Oppo Phones.
Step 1: Navigate to the Phone section.
Step 2: Tap on the menu with three dots and select Block Harassment Calls.
Step 3: In the Block Settings window, activate the Block Harassment Calls feature and then select Block List.
Step 4: Tap on the Add button at the bottom of the screen.
Step 5: Proceed by selecting the Manually Enter option.
Step 6: Enter the phone number you wish to block and press Add.
Step 7: The phone number has been successfully added to the block list, and that person will not be able to call you anymore.
By following the method described here, you have successfully blocked calls on your Oppo phone. The caller will receive a busy signal, and you will also receive a notification indicating successful blocking. This method is very useful without the need for any additional third-party apps.