I've been a fairly well satisfied Vonage customer for 7 years. I have had trouble with intermittent poor line quality, but it has never been clear whether this is a problem with my ISP. I've often found that the quality of customer service is poor, but I've not had alot of reason to call them except to make changes in my service.
However, when, after porting out my phone number and making sure it worked on the new phone service, I called Vonage to cancel my service, they made it very difficult to cancel service, gave me a very hard time, and tried not to cancel my service. This was month to month service; I did not have a contract, and I did not expect a partial refund for cancelling in mid month. I actually cancelled the day before the month ended.
You can't just cancel service online. I called customer service. First I got someone who insisted that my number hadn't been ported out. I checked to make sure the port was complete and the phone number working correctly on my new phone service before trying again. Then I learned that while all other Vonage customer service is available 24/7, you have to call between certain hours and talk to a special office to cancel service. Then when I called back, the customer service person insisted I tell her why I want to cancel service before she would transfer me, and I had to shout at her four times that I don't have to tell her anything, transfer me, and she actually transferred me when I told her I'd changed my payment method to a card with insufficient money available for Vonage to get their hands on it. When she put me through, a Chinese guy kept demanding to know why I was cancelling my service, and insisting that I had to do cooperations with him, before he would cancel my service. I had to shout at him six times that I don't have to tell him anything, I don't have to cooperate with him, cancel my service, NOW. He finally cancelled my service when I told him that I changed my payment method to a card with no funds available, and Vonage won't be able to get any more money from me, ever. The whole experience was completely outrageous, and at this moment, I can't recommend anything about Vonage to anybody.
Product or Service Mentioned: Vonage Phone Service.