Internet acting up suddenly - incompetent support staff

Hello.

On Wednesday of this week we transferred our service to a new house. We have a cable box and a modem already that both work FINE. So the technician shows up with huge glob of dip in his lip and hes like "oh y'all already got everything you shoulda just hooked it up yourselves". Well we didn't because we didn't want to mess with anything or maybe damage the wires by pulling them out of the wall or whatever.

So he brings in some wire extensions to allow the cable wire to reach the modem/cable box and as soon as we plug things in they are working fine. He says "ok y'all good do you have any questions?" I said, "No sir! Have a good day and thanks". About 10 minutes later I hear him grunting and snorting and spitting outside my window where our wiring and stuff is, and then the internet cuts off. He comes back in and says "Did your internet cut off?" "Yes, yes it did but it was working fine." He says, "Yea I was afraid of that I mightve cut the wire outside" so an hour goes by of him talking to someone on the phone about the issue and eventually it is fixed and he leaves. 

Internet works fine until yesterday around 6 pm. The modem (Netgear N450 CG3000Dv2) lights all turned solid blue/green and remained that way for a good 10 minutes. I waited to see if it would correct itself but it didn't so I attempted a power cycle. The power cycle corrected the issue for about 30-40 minutes and the same thing happened. So I power cycled again. Same result. When it happened the third time I got on my cellular data and searched the internet for options and ended up going through Cox's connectivity troubleshooting options where it states to refresh my computers IP, etc. I performed all of the troubleshooting options I could and still the problem persisted. So I used my phone to access the "modem reset tool" via the Cox site for the next 2 times and I maintained internet connectivity until I fell asleep.

I woke up to 6 solid lights on the modem and knew that it had happened again. So I power cycled, the internet came back on and I immediately contacted the live support.

Me: -explains my internet issue in detail-

Tech: I see lets try to reset the signal to your modem.

Me: If that is what your "modem reset tool" does i've done it already.

Tech: I see maybe it time to send a tech out to troubleshoot further

After being with Cox for over a decade im convinced that none of their employees know anything. The last time a tech came out we were charged 75 dollars for him to hook up a little machine and say "everythings fine on my end must be lead paint on the walls or doors, I suggest buying some fancy new equipment to strengthen your wifi signal" They always suggest upgrading or purchasing something no one ever actually tries to fix the issue. 

So, depending on the outcome of this thread and if someone manages to help me with my problem, I will suggest to my mother that we change internet service. We've been with Cox for a very long time and have had regularly occurring internet problems with the High Speed Preferred package. 

thanks for reading and thanks in advance for any help or information.