To block a number in the OneCloud
Log into your account at myonecloud.com
Select Answering Rules from the top of the OneCloud WebClient.
Click the Allow/Block button located towards the upper right-hand side of the page.
Once the Allow/Block popup window opens, locate the Blocked Numbers section.
Click inside the Enter a Number text field and type the phone number you’d wish to delete.
Click the plus sign to add the number to your blocked list.
When finished just click Done.