Irritating telemarketers!

So. I am all onboard for trying to improve marketshare and increase sales. But for heaven's sake, if I've been called 20 times with regards to a previous contract that I can upgrade, and I've explained 20 times that I don't want to upgrade the contract... One would think that you'd no longer be harassed. Apparently this is not the case. So, since the agents that keep calling don't understand the whole principle of 'I'm not interested, please stop calling', I'm hoping this post will get the message through!