Supersonic downright unusable

We've had the most terrible speeds on our fiber for over a month. We pay for a 100mb up and down line and we get nothing of the sorts. It is really unstable and sometimes the jitter is so bad (96ms) that we have continued packet loss. I phoned Supersonic's call center today and they weren't helpful at all. They asked for my number, said they'll check the line and asked me to hold on...26mins later.. no sign of them getting back to me. Service delivery and customer care extremely poor. I am looking for a new isp that actually delivers what I pay for.