How to I get someone to fix an issue within comcast network?

I have a documented, chronic packet loss issue between hops po-400-xar01 and be-306-arsc1. The loss correlates with severe real-world traffic stuttering on a strict 30-minute interval. My local equipment has been ruled out. I need this escalated to Tier 3 or network engineering to investigate node infrastructure stability in Salt Lake City.

be-306-arsc1.saltlakecity.ut.utah.comcast.net is dropping 50% of packets. It's the hop right after po-400-xar01.saltlakecity.ut.utah.comcast.net. Up to that point my internet works well. This has been happening every 30 minutes or so for months.