Gigabit - 3rd Party Modem Reprovisioning

@ComcastChe - I need your help.

I have been trying to get someone at Comcast to assist me for weeks with no luck; I have spent four hours today alone. I have a Motorola MB8600 modem and I am paying fot gigabit speed, but only getting 250mbps..... Motorola told me that the incorrect speed configuration/boot config file is attached to the modem. I have been desperately trying to communicate this, but I cannot get past tier one support. Their canned response is everything is fine on our end, you need to call Motorola...