Iphone 4 upgrade after two years?

So I've had my Iphone 4 for two years now, I'm in desperate need of a new phone. My lock button is broken, my home button sometimes freezes up, my front screen is cracked and the back on my phone is missing chips.Yeah i wasn't so responsible with this phone. But i heard that i can get an upgrade after two years? If so, can i upgrade it to an Iphone 5s? I just wanna know so i don't look like an idiot with all my questions when i go in at rogers next week.

Yes you can! I done it after my two year contract was up!

Most cell companies do two-year contracts but some do three. Check with your provider to see if your contract is up then or not.

And once it is up, you can get a new phone with a new contract at new-contract prices (the $100 instead of $600 or so). You can usually upgrade a month or few before expiry for those same prices and a few months before that (3-6 months before contract end) at reduced prices closer to 50% of phone cost.

And the questions aren't stupid, the whole point of cell phone stores is to answer questions.