Can I switch phones before my 2 year contract?

So I have Verizon and I got the Samsung s8. I know they let you switch as long as you don't hit the 14 days, but it's been a little over a month and I wanna go back to iPhone. Is it possible to switch? If So, how?

HOW TO SAVE IPHONE VIDEOS?

A couple months ago or so, I had problems wit my bank card in general and wit my iPhone. I could not remove my details from the phone, and I never got to the point to upgrade my storage again each month. I broke my phone and when I got it fixed my phone completely reset itself. I put all my details back onto the phone and I still had to manually install things but I think I lost all my things.
Anyway, I upgraded my phone recently to the "iPhone X."
I had secret videos on my old phone and I'm guessing the iCloud? I'm now using a different iCloud but I remember the details to sign in to the old one.
I had amazing videos of a ufo I saw, and I had it recorded on my phone. As I never upgraded my storage I realized they disappeared. If I logged in to that iCloud on another device again, and I upgraded would it restore what is deleted? I already know it says "it deletes deleted photos after 30 days forever." But I never deleted it. Or sucks as it is real footage and I feel like this is can't be over.

IPhone 6s storage almost full AFTER restoring

My iPhone 6s is up to date with IOS 11.2.1. I have the 32GB phone. I've restored my phone from settings multiple times and still says my memory is full with NOTHING on my phone. No apps. No pictures. No music. I've hooked it to iTunes & tried to restore it from there as well but it wants to update it first THEN restore it but it's already up to date with the latest version of iOS therefore it stops midway with an error message & I can't restore it from iTunes. If someone can help it'd be much appreciated!