My only brother not coming to my wedding

I need to vent. So after I chose my wedding date(october 20th) I told my younger brother and my family of course. My younger brother who will be 21 in April plays college football in south dakota. He told me he would try and make it to my wedding even though there will most likely be a game that day. I told him over a year in advance. my mother told me, "They don't have any subs/extra players, so they need him." I understand football and college is important but you are telling me that those football players can't miss one game for a family event? My mom keeps telling me, "Well he signed a contract and that puts a limit on what he can and can't do." What kills me is that my mom doesn't even really care about my hurt feeling about my only brother not wanting to or can't come to my wedding. I am trying not to be hurt about this but then just now my 16 year old cousin who said yes to being a bridesmaid told me she might have a volleyball game that day so she doesn't know if she will get her hair and makeup done. Wedding are supposed to be happy and so far it's been nothing but hurt feelings.