Pathetic VoIP service - doesn't work but VOX doesn't care.

I'm paying for the VOX VoIP Service -and being invoiced for it each month. But it's not working. When trying to make calls, I get a message that my account is not registered. This has been going on since mid november. I reported it to VOX a countless number of times. And asked for a refund of the monthly VOIP Fee for the months it has not been working. No one cares at VOX - they are not even replying to my emails