Are you sure they weren't moved to Separate Support Required or Resolved Issues (happens sometimes after a thread becomes inactive long enough--especially when there are duplicate threads). If they were straight deleted, it may have been because duplicate threads were already up and active...could have been done by policy or because enough people reported it as such.

As for the ISP's potential culpability with your connection woes... they may have actually told you more than you realize by saying nothing has changed on their end. That may in fact be part of your problem---something may need to be changed in your route because it is getting impacted by bad latency/packet loss. May want to trace the route to see if anything sets off any red flags.