You can block an inbound number at the user level. Below are instructions on how to accomplish this.
Log in to MVP
Log in to the voice portal at https://www.myvoiceportal.com and enter your username and password.
Navigate to Answering Rules and then Allow / Block. This will give you the option to add a number to permanently block at the user level.
Allow / Block
Enter any numbers you want to block in the Blocked Numbers side. You may also choose to block Anonymous or Unknown numbers. Click on Done when finished. The changes are applied immediately.