I bought a new phone and now im having trouble with it. what should i do?

I had the iphone for a couple of months and i loved it but about a month ago i went ahead and bought a blackberry. and ihave had a horrible experience with it. and didnt notice until a few days ago, but im lucky if my battery lasts even 4 hours, and i get no service anywhere. so i went to my carrier and spoke to them,and they diagnosed my phone and told me that it was defected, but they have a 30 day exchange fee, but they cudnt give me a new phone, because im 6 days past that, they said i could exchange it at another store, but no other store has the blackberry that i have. so from the store i called the costumer support and they said that they could exchange my phone for a refurbished phone. but no thanks, i mean 36 days ago, i paid 500 dllrs for a new phone, and im not going to accept a refurbished phone that can cost like 50 dllrs because the store sold me a bad phone. what is that???!.... and let me just add, i have no problem having a refurbished phone, its not like that, its the fact, that the store sold me something bad, which should mean, that if i paid full price for something i should get back what i paid for, if i paid for a refurbished then i shud get a refurbished phone back. it just makes no sense…. and they said thats the only thing that they could do to me.
any ideas on what i should do?