Not getting Gigablast speeds - Henderson, NV

I have had Cox Gigablast service for the past year and half. Over the past couple months my speeds has been slow and no where near what I am suppose to be getting. I work from home for a large technology company and very familiar with tech devices and equipment. I have online video conference meetings few times a day through Microsoft Teams and Zoom and cosistent fast speeds is crutial to my work which is why I chose Gigablast through Cox. Lately due to my slow speeds my meetings quality has been terrible and freezing up constantly, and I have to reboot my computer and my modem all the time to no help. I have contacted Cox support couple times for help and they constantly try to tell me the problem with my equipment and to disconnect all my devices and run speed test while hard wired directly to the modem and still keep getting the same result. There is absolutrly nothing wrong with my equipment and the issue is either on their side or I feel like I am being "trottled" for some reason. I pay $120/month for my service and get no where near the service I am suppose to be getting. Sometimes I can't even stream movies as they freeze up or the quality is sub par due to slow and intermitent speeds. With Gigablast I am suppose to be getting 900+ download and 30+ upload speeds and over the past couple months I am getting 60 - 150 average download and 10 - 15 average upload speeds. These speeds would be good if I was getting a basic to medium internet package but not for Gigablast. I have never been getting the 900+ and 30+ speeds but at least I was getting 600+ and 20+ few months ago but lately it has been horrible and it is "NOT" my equipment!!

PLEASE HELP!!