the new ios version downloaded to my phone and waiting to installing but i dont want it

I have an iPhone 4S, version 7.0.4 -8G.

I am very disappointed of the product.

Lately , the OTHER category memory mode takes a huge place in the free space on the device about 2 GB.

Because through iTunes can't remove memory in this category (OTHER), I decided with great regret reboot the device.

And now after rebooting the iphone, I find the new version of IOS 8 automatically downloaded (and waiting to installing), covers memory device under the category OTHER.

It's not fair that I paid for this device 450 USD and got a product that is managed by you.

With great regret I'll buy a new device, which wasn't produced by apple.

Very disappointed and sorry about buying this device.