High Def Sports

I pay extra for "sports" programming.   I also pay extra for "High Def".   Right now the US National Women's Soccer team is playing Canada on channel 737 which is NOT high def.   Everything I read says it is available in high def but Comcast won't provide me acces to the channel whatever it is.   I know they do this because they are witholding other local Washington D.C. channels to force me to watch Baltimore editions.   You guys are terrible.