Can apple really take my iPhone away?

Long story short my husband bought a 340$ paperweight off of some shady people on offer up, when a Sim card is inserted it says no service. A nice guy at our carriers local store said to go to the apple store and get it exchanged for credit. Even better the phone is under warranty so we can exchange it. However we hit a bump when the apple "genius" said we can't exchange the phone right away because our particular phone got flagged to go to the "depot" they couldn't tell us why. At some point the guy said if they used 3rd party parts they're going to keep the phone and they do this as a deterrent. Can they really just take peoples property like that? There's confusion about this just because I asked again and he said something different, I couldn't get clear answers. At the least my spouse has learned a 340$ lesson in listening to one's gut, and at most it might work out and he gets a nice phone. I just can't believe that's legal.

How to restart my iPhone without deleting everything?

I have an I phone 5c. I was on the internet and I accidentally clicked on this web site that said "webcam now installed into your device" or something close to that and I don't think that can really happen but just in case I closed the tab and held down the power button on my phone to restart it. Then about 6 hrs later I got a text with 3 random picture of like cartons or something. And just a minute ago my phone went black and Siri and vibrate was still working, and when I plugged my phone in it vibrated like usual. But the screen wasn't working at all. I kept holding down the buttons and eventually it turned back on. These could be huge coincidences, but I want to be sure there isn't a virus or anything wrong with my phone. How can I check for a virus or reset my phone, other than plugging it in and deleting everything?

Will T-Mobile replace my iPhone?

I just got a replacement iPhone 6 and IIm paying the monthly insurance thing(5 bucks I think) and I read that the replacement iPhone has 6 month warranty. I accidentally dropped my iPhone a few days after it arrived and the screen cracked. Will T-Mobile be able to replace the phone without any major fees?

Added (1). Is there anything I can tell them so they won't charge me like 200 bucks? For example if I tell them the battery drains too quick or that it keeps freezing?

How to recover deleted contacts on my iPhone 5s?

There are some numbers that I deleted from Contacts and also Recents, but I d like them back. Is there any way to do it or any app that can do it? Also, I wasn't using iCloud or syncing contacts with iCloud.

How to send iPhone text messages through my PC?

I have an iPhone and a PC windows 10 laptop. I was wondering if it was possible to send iPhone text messages from my PC. Like for example, if I wanted to text my friend, I would send it from my computer, but on his phone, it would say that it was from my cell phone number (an iPhone). I used to have an Android and there was an app called AirDroid that would allow you to do this, but on iOS, there's no AirDroid or a similar app that allows you to do so. I know that you can do that if you have a mac, but I don't have one (they're too expensive in my opinion). Also, I do not want to jailbreak my iPhone, so please do not comment to jailbreak. If anyone knows a solution, Please tell me, as I'm tired of texting through my iPhone screen.

Thank you in advance!

Added (1). I live in Ontario if that helps with anything.

How to put my music on my iPhone from my MacBook Pro?

I just got the iPhone SE and I'm having trouble putting my music on it. Whenever I plug my phone into my computer it says that the iTunes version on my iPhone is outdated but i'm 99 percent sure its the most current one. Also I'm not sure if this affects it but I have different apple IDs on them. Any advice?

How to conserve iPhone cellular data?

I'm in high school and there's a new policy where your allowed to use your phone in school. Your only allowed to use it during class if your teacher tells you but during your free time you can use it whenever you want. I turn off my Wi-Fi because our school blocks almost everything even things such Nick Jr. And music and you have to go through this complicated process when registering. I turn off cellular data for all of my apps except for a couple that I use frequently such as Instagram, Snapchat, Pandora Radio, Safari, and a couple apps that use very little data. I still use so much data and I really try using less but I still use a lot