Well, Zen Internet is no longer as good as it used to be. They certainly have made a hash of changing static IP addresses, taking away the ones you had for years, and then allocating another range and expecting you to pay for them. And then we have disputed bills, which Zen Internet have not resolved the issues. So previously I would have wholeheartedly recommended them, but now I put them on par with PlusNet. They're not very good now.
I've already cancelled 1/3rd of their services and I'm awaiting the remainder contracts to expire.