Non-stop campaigning telephone calls

I have been receiving regular (weekly and sometimes more than once a week) telephone calls from the DA asking that I vote for them in the upcoming by-election. Despite my request that they stop calling me these calls have continued. I then posted a request on their website that they remove my contact details from their database because these calls are now becoming a nuisance as they are always when I am at work and I regard them as an harassment. I received a call today, which I ended and no sooner had I ended it than the person called again, from the same phone number - ***. Needless to say, I ignored this call.<br> <br> How do I get them to stop harassing me?