iphone 6 screen cracked

I purchased my iphone 6 around 7 months ago, and my screen got cracked by accident.

I still have a warranty. I'm thinking about getting my screen replaced at the apple store (in Canada).

and I wonder if my warranty will cover the cost of replacement because I heard if something happened "accidentlly", the warranty won't cover.

If it won't, I wonder how much it will cost to change my screen in Canadian dollars, and also how long it will take.

AND

I heard when my phone is transferred to apple care centre, and if there is any other problems beside my screen (such as battery problems or minor scratches)

they're gonna automatically replace to a new phone without the phone owner's permission.

IS THIS TRUE? I was shocking when I heard this because it costs almost $500, and happened without letting know the owner and permission.

I also heard that when my friend complained about this non-sense policy, Apple said the owner has no option but to follow the decision of the Apple Care.

She paid around $500 first, and was told that, after Apple Care decides if this phone doesn't need other repairments besides cracked screen, she will get a

half of the money back (I guess other half is for repairing cracked screen).

IS THIS TRUE?

I WOULD BE MUCH APPRECIATED TO GET ANSWERS. THANK YOU.