How to get Cox to stop throttling my service?

I've upgraded my modem back in early summer to a DOCSIS 3.1 since Cox decides to lie that it couldn't handle the 500mbps service I am paying for. Since then I am still only, constantly, pulling between 250-300mbps even though I pay for the Internet Ultimate 500 package. I talked to a rep who misspoke and said I am still on a 300mbps line, but then said he found that I was on a 500mbps plan. I am 100% sure Cox is throttling my service and I'd like to somehow speak to someone who isn't in a chat center in India who understands that 1) it is not my equipment and I don't need to be sold into the horrible panoramic wi-fi controlled by Cox, 2) I do this for a living, 3) sending a tech at a cost toward me is not beneficial in any capacity, and 4) can understand that I need them to reconfigure the port on whatever switch they have to allow through my paid for speeds. 

Does anyone have any insight on how to get a hold of someone higher than a level 1 read-from-a-prompt support "technician"?