Will my iPhone carrier let me know when I've used up my monthly 4G?

I have an iPhone 5, and my carrier is AT&T. My sister has told me that the day I pay my phone bill, I can use 4G until the 30 days are up and I have to wait until my next plan to use 4G again. I'm really anxious because I can't tell how much data I'm using and when I should stop before I'm charged for going over the limit. I've gotten a text from AT&T saying I had used 65% of my data, so will they send me one for when I use all of it (100%)?

How much to unlock iPhone 3GS? - 1

My boyfriends sister just gave me her iPhone 3GS but she's on Tmobile and I'm on O2. I don't get along so well with my own phone so I'm really keen to have the iPhone. Anyone know on average the price? Plus the safest way to do it?

Any REAL sites to test and keep an iphone 5?

I really want an iphone 5 but i want to test it first to see what it is like are there any sites known to actually give you the iphone 5 i don't want to know any fakes or that they don't ask because i know there are a few i just don't know which ones help please!

Added (1). No simulators i want the iphone in my hands please thank you

Selling price of a used unlocked iPhone 4?

I have an iPhone 4 which I have had for nearly three years, my contract ends in a month or so and am planning on buying an iPhone 5 so I want to unlock and sell the 4 when I get it. The screen is in near-perfect condition, the back panel is also nearly perfect, however the sleep button has lost some of its 'clickiness' and one of the speakers has died, and there's some of the silver come off around the metal bit around the sides, how much do you think I would be able to get for it on eBay for it? (The software still works perfectly aswell btw)

What happens when you download a movie from your collection from Flixster?

What happens when you download a movie from your collection on an iPhone from Flixster? Does it actually appear on your iPhone under "Videos" or is it just installed on the Flixster app, so that you can watch it without streaming the internet?

New iPhone 5 but all games gone

I upgraded my iPhone 4 to iPhone 5
I transferred my number so it's the same
I re downloaded all my apps
However all the games have started from the beginning even though in the game centre all my scores are still there, what do I dooo:-/

My iphone 4s won't charge on wall but charges only connected to computer?

I got an iphone 4s which is used. I bought a charger today but the iphone doesn't charge
on wall. Only in the pc.

How to make iphone battery last as long as possible?

Going on a last minute camping trip tomorrow and as with all iphones the battery goes quick, well mine does anyway. Any tips to lengthen the battery life? Have a iphone 4s, Thanks

How to i sync my Iphone 4s to new computer without wiping it?

My Laptop broke where i synced my iphone 4s to. And i want to sync it to a new computer. Is there any way to do that without wiping my phone? Or save all the information and back that up after its synced?

Which cell phoe carrier is right for me?

I want to upgrade to the S4 from an iPhone but I'm sick of paying $100+ a month for AT&T. My contract expires soon and I want to switch carriers. The problem is, I just don't know which one. I want to spend about $70-$80 a month for unlimited text, doesn't matter how many minutes and at least 2GB of data. I like T-Mobile's pricing but I don't like the idea of paying $25 a month for the phone. I also don't want to spend $400+ to get the phone through lesser tier carriers. Any suggestions? Thanks.

Added (1). I saw I spelled the title wrong. Oh well.