the unable-to-cosplay-stress

like the title said, unable to cosplay..
its been months i've plan for this event, Animangaki
i've got my new costume, new wigs, everything set and done
suddenly a breaking heart news from my mum is, she force me to go do rebonding.
i'm totally fine with it actually, i even told her please don't set the date on 25&26 august cause i've got an event to attend.
she purposely set it on 25th and say its a must to do.
ok fine, i discuss with my best friend about it.
its my best friend 1st time going to cosplay and i abandon her and the plan. HOW AM I HAPPY!!
and so i think of goin on the plan with her and cosplay.
good thing is my wig is a long straight wig, bad thing is my hair is brown and my wig is purple.
i'm still very stress if i am able to cosplay with her during the event.
I really don't mind going less 1 day, but i mind alot about my friends.
I really really don't know what to do.
my mum wouldn't listen to me about changing the date. i just hope she would listen and change it for me.