Iphone 5, 5 months old, will it be able to be replaced?

So i bought an iPhone 5 (16gbs), 5 months ago and as soon as i got it, battery life was significantly poorer to my friends one. Her one lasted 8 hours from a full charge with heavy use everyday. My phone barely lasts 5 hours from a full charge with very minimal use. I have also noticed that the phone becomes very hot even when its in my pocket. 2 months in with my phone all of my apps started to crash regularly so i took it back to my network store and told me that i was to delete my photos because there was not enough room on my phone. There was 10gbs used of the 16gbs which i thought was quite rich. My camera also has trouble focusing. The amount of times that my apps crash is getting more frequent. I think its ridiculous to pay $1000 for a phone that hardly does its job. It is literally the worst phone i've ever had. I've had $100 phones better than this.
I also have insurance, not apple care but with my network.

Your battery life problems are not unusual, particularly if you have certain apps installed and they're set to poll for updates frequently. So you might want to check how many apps you've added (especially social networking ones) and their settings.
You'll also use more battery power if you connect via your cell connection rather than Wi-Fi. Turning off Wi-Fi and BlueTooth when you're not using them also extends battery life.
If you travel a lot each day then that also uses more battery power as your phone has to constantly reconnect to new cell masts.
But there's natural variation between individual batteries and phone circuitry which can combine to shorten the time between recharging, and your phone is within the lower end of normal limits.

If you can't live with it, back up all of your data, reset the phone to factory specs, and sell it. Use the proceeds to buy something else to use on your current contract, but note that the most powerful and feature-packed smartphones will all have fairly short battery endurance.