cancelling Bulletin subscription

Is this possible? Delivery has been erratic - I received the first 'new look' edition 1 week later and only after I emailed to ask what had happened to it, and the 2nd edtition failed to arrive at all, despite emails sent and read. I was told I have a year left on this subscription. I have no interest in the Bulletin now as it doesn't provide all the listings that I am interested in. As they are not delivering it, I don't wish to pay for it. Is it possible to cancel the subscription and if so how? They are not answering any emails.