Is it wrong to feel saddened by this? Am I just stupid?

So we've never had a lot of money in my family. And always are stuck to prepaid crummy phone plans.
So my mom saw this plan online and she said she would get my brother and I iphone5's. Well she said That Saturday we'd get them.
I was litterly so excited! I had wanted an iphone for like ever. My phones have always broken after 6 months. And my phone is screwed up and breaking right now.
So I worked really hard to be able to earn the phone, every single day working for a long time. I picked out a case that I wanted and I was really excited.
I'd also have to sell the phone I have now, so I cleared through all my apps and pictures.
Well we went in there and ended up not being able to afford them. It disappointed me so bad!
This stuff always happens, and I always get my hopes only for this kind of stuff. I mean my phone is like almost broken, I can't get an iphone ever because I'll never be able to afford one.
And my mom is still making me do all that work.
Am I just stupid?

You're definitely not stupid. If you and your brother want to get iPhone 5s, maybe you and your family should work together to save up for them, and set out a little plan on how you're gonna do it. You said your family doesn't have much money, so it may take a while, but you will eventually get there and save up enough if you manage your spending habits.

You aren't stupid. However, your mom appears to be under stress (financial stress, and she may be feeling inadequate because she can't give you what you want, which always is hard on parents).

All I can tell you is that in order to be happy, you have to learn to accept the lack of material things. The phone you wanted would make you happy, sure, but it isn't worth being too upset about.