Speed Fluctuations

I have the premier cox service and frankly, the delivered speeds ***.  At times the speed tests time out and after restarting, the download speed maxs out the speed meter.  There is simply no consistency.  I cannot count on reliable internet access at almost any time of the day.  It may be great and it may be non-existant, or it may be deadly slow.

Cox sent out a representative and his advice was to get a dual band router.  The poor guy simply could not get it that I am using wired connections and have the wireless option turned off on my router.  Talking to him was like talking to a nice McDonald's clerk about sushi.  He could only talk in hamburger (wireless) solutions.

My modem was replaced on warranty as it was possibly bad, but this has made no difference.  Calling in is a total waste of time as usually I get the "known problem in your area, fixed in 24 hours" replys.  Just how many problems are there in my area?  Do we need a fulltime repairman for my neighborhood?

Any suggestions as to how to proceed?