blocking people from calling on vodafone

Hi, just looking for any insight/experience into the possibility of having annoying calls and texts blocked from ringing me. As far as I know, vodafone do not offer this choice, however some people say that some phones offer people the opportunity to do so. I do not want to involve the gardai as It's annoying more so than malicious and the person that is calling/texting me was once a good friend, who also sufferes from an addiction problem. My Brother and friend are EMobile and o2 customers respectively, and I know that those companies easily offer the choice of blocking people simply by request of the customer. I can't understand why a big company like Vodafone can't do likewise. I would love to stay with vodafone, but it is really pissing me off. So please anyone with any knowledge of phone allowing for blocking, lease respond:(