Contract Loophole

My 7 year old daughter joined a competition cheer team this year. We signed a contract at the start of the season. My daughter was unable to attend a competition due to having flu A. She had a fever (that medicine wouldn’t break), body aches, chest congestion, etc. There was no way she could compete at this competition that was 4 hours away. We had been in communication with the coach all week giving daily updates. She did not attend any practices that week which was excused by the coach. Due to her not attending the competition, she was dismissed from the team. They are now billing us for the remainder of the fees for the season which was said in the contract. The contract states that a competition cannot be missed except for extreme circumstances that have been discussed with your coach. There are no examples of “extreme circumstances“ so this could be interpreted differently. Do we have a case? Especially having a doctors note for proof?