Upgraded Modem to Docsis 3.0 and to Premier plan,but not seeing any increase in speed

I upgraded my modem to a Motorola SB6141, I activated it with no problem, I then upgraded my Internet to the Premier level, I ran Speedtest and the Download speed is exactly the same as I was getting with my old Docsis 2.0 modem and the preferred plan. I called customer service and we went through about an hour of troubleshooting with no solution, They scheduled a Tech to come out and he checked everything and said all signal levels and connections looked good, said that maybe it has not been upgraded in my area yet ??  I find this a little hard to believe because when I called customer service to upgrade my internet service, they upgraded me to the premier level, I would think that if it was not upgraded in my area that they would not allow me to upgrade my service... Should I just return the modem and go back to the preferred level ?  I saw some posts on here about a code that needs to be on my account to allow the higher speeds, Is there anyway that I can have that checked ?  I would think that since I spoke with customer service for over an hour troubleshooting this and a Tech came out to my house that someone would have checked and maybe double checked to make sure this code was on my account... Is there anyway to make sure it is actually there ?