I dont want to hurt her feelings and she went to all this trouble...?

My mom bought my a bamboo art tablet, I didnt even kno what it was and since my sister was getting one i wante one after all the awsome stufff she told me about it. So my mom bought her one and me one. I get home and it sucks. I dont want it. 150 buks on something thats gunna sit in my fuking drawer all day, i thought it was like a normal apple touch tablet but its no were close. I feel so bad about making my mom buy it and i tried being honest with her- i said all that i can and she kept telling me its ok! Dont worry about the mony its ur BD present. I would rather get a camera or a cellphone. I dont want it, please what should i do? I WAS TOTALLY HONEST WITH HER and she wont give it up