Continious sales calls and not taking no for an answer.

Hi have a 0 balance Edgars account. They seem to see this as a sign that i have money that needs to be milked. For the past 2 weeks I've been getting calls twice a day from Hollard on behalf of Edgars trying to bully me into buying Funeral and Life cover. No matter how many times I say no they keep on phoning and actually getting really pushy about it. I've reached the point where I want to close my account, but now they are giving me the run around and offering to increase my limit rather than close my account???????????? I want my account closed, and to be never contacted by Edgars to ever again.