You can block a contact to prevent them from calling you, sending you instant messages, and seeing your presence status in Skype. In addition to blocking a contact, you can also choose to report abuse. This notifies us of spammers, so we can stop them in the early stages of their activity.
Note: If you receive an unwanted call from an unknown phone number, you'll have the option to block the number right from the chat. Simply select the Block + the number link to block that number.