How do you solve interpersonal problems when neither sides can see themselves as the one in fault?

I've had a a fight with my sister regarding my birthday present. She bought me - boosted with a contribution of my mom and dad - a bunch of clothes. I naturally got mad because: 1. it's a large investment for an unsafe return (my disappointment) 2. I always hated getting clothes for my birthday and the trend haven't changed. I always just asked for money instead.

It has caused a little bit of bitterness. I understand her point of view, which was to make me happy on my birthday but I still can't excuse the invalidity of the function she was using, especially considering that I previously mentioned that I hate clothes for birthday.

What should I do in order to ease the situation? Also, do you think that my reaction was inappropriate?

I talked about this with other people and what people said was 'it's the intention that matters' and that sounds like an excuse (and at this point I'm curious if I actually am looking for criticism or just subconsciously hoping I'll get a bunch of chocolate frogs) so get the best criticism you can give.