Harassment from the call centre

This company either has the stupidest system or their agents do not listen and follow through. <br> <br> They have been phoning the office where I work asking for this gentleman who left the company a year ago. We keep telling them to update the system and remove the number it's been more than 2 months now.<br> <br> Today alone they called 4 times already and they are not willing to put me through to their superiors to address this issue.<br> <br> I am close to getting someone to harass and call them every 30 minutes.<br>