PLease help me !!!!!!!!!!!!?

So i have asked for uggs fro christmas and i notiiced todayy that my mum has got them fro me o m ake them not as big on me D i no it was wrong but i tried them on i couldnt resist i noticed that they were to big for me =S i cant tell me mym um that ive tried them on and it will b hard to s end it them bk and cost a lot of money, and they would last llonger coz when my feet grow i will still b able to fit into them but ofr now when christmas comes and if they still are to big what can i do to make them not as big for me ?