50mbs speed

Just upgraded to 50mbs service today. As instructed I unplugged my modem, waited 30 seconds plugged back in. Did a speed test using cox,com test and speedtest,net. Max I am getting is 32mbs per second. Why is this? I have the latest modem.. Everything is hardwired using cat 6 cables. Called tech support and they had me try a couple things but the speed has not changed. They are sending a tech out to the house but not sure what that is going to do? Any suggestions?