What a disappointment

My brother made a mistake when booking my flight with Air Botswana he put my ****en name instead of my husband’s last name he ddnt know l had changed my Passport to use my new name ,However Air Botswana has refused to help me they said l should cancel the ticket and lose all my money..Tried telling them l can produce my marriage certificate and all but it’s falling on deaf ears …I’m really disappointed ☹️