Vonage No way to cancel service. Won't take cancellation by email or chat. When you phone in, they run you around and around (1 hour and 22 minutes!) and finally hang up on you!)

I am retiring and moving out of country so need to cancel my Vonage phone service. They say online they won't take cancellations except by phone. I called five times this afternoon and was hung up on five times after I explained that I needed to cancel. This evening I waited 1 hour and 20 minutes to speak to cancellations, and kept being passed from sales to tech support, whose agents all said they could not cancel the account and they would have to transfer me. In the end, the tech support fellow just hung up on me again. How can I cancel?