Keep on charging me long after account closed

One star is too many for this company. If you want to spare yourself a lot of headaches dont even look at them. I would pay 10 times more at any other company just in order to not deal with thsis incompetence. I cancelled my landline about 14 months ago. I made double sure i cancelled it as i have heard they keep on charging people long after their accounts have been cancelled. My account was clear on their website, i got an email stating its cancelled. I phoned and after 20 minutes someone picked up and this person confirmed my account is cancelled. Now a year later i get summons that I owe money for the whole year and i will be blacklisted if I don't pay. How is this not ********. This is the only reason this company is still in business. I have never had a worse experience at any other business