The billing department listened to my situation and went back to supervisors to get an update. I was then advised to cancel FTTN and go back to a reliable POTS line with failing DSL. I had been advised by Sonic to upgrade to FTTN because the DSL line was very unstable and obviously failing. They said they'd refund the FTTN charges since install. I was dumbfounded. Sonic seems overwhelmed to provide internet/VOIP.
Since I can't get usable DSL from Sonic+ATT anymore, and FTTN/VOIP seems beyond them, I'm going to recommend to people I know that they look for bare internet and if they need a VOIP phone then find a cheap VOIP provider. That combo out here would be $10-20/month cheaper while not being locked into phone service from a particularly provider.