Varying speeds

Hey I have had Cox Premier for about a year and a half now. I have had more issues than I can count. My biggest issue is the speeds are nowhere near consistent. I am a gamer and my playstation 4 is not getting the speeds that I am paying cox to provide. I have had my PS4 serviced twice and nothing is wrong with the PS4. I have had my router and modem replaced 3 times in the last year. One minute I might get 20Mbps down and 5mbps up and then the next minute I would get 80 down and 7 up. I have had technicians out to the house 7-8 times in the last 6 months and every time they come out and run the in home tests, everything is fine, they find nothing wrong. I have called playstation and cox both numerous times and now I am just tired of getting the run around. I would like some answers.