Having problems resetting an iphone to factory settings?

So this is about to be a huge wall of text and I'm really sorry about that but I've gotten to the point of not knowing what to do anymore.

Basically i have an iphone 6 ios 8.3 and my sister tried to jailbreak it for me. I agreed and she got it to work but there was an error with Cydia and I could no longer download apps from the appstore. I also couldn't get into Cydia because of a dpkg error. I tried to reboot the Iphone to factory settings using Itunes because that was the only way i knew how but it wouldn't work. The first few times it tried to reboot to factory settings it flat out would give me errors telling me something along the lines of "Software could not be downloaded, network error" and then i tried one last time, it didn't give me errors the entire way through resetting but when it finally finished downloading the 1.8 gigs of data nothing happened and my Iphone remained in the same state it had been in, nothing deleted or reset. I found you could reset the Iphone through general settings (i DID NOT know this would completely mess up my phone because it's jailbroken) and attempted to reset it through there. Now my phone is stuck on the reset progress bar. I tried resetting it through itunes again but i'm still getting errors I really don't know what to do i've been searching on the internet pretty much all day and trying everything. I don't think i can go to apple to get it fixed, once a device is jailbroken i think it no longer has warranty? Please someone help

Added (1). i'm sitting here trying to reboot it through Itunes again and the phone just flashed a blue screen and reset back onto the reset screen for general settings reboot. ;m;

How to unlock disabled Iphone 4S (forgotten passcode)?

So I went to change my pass code on my phone, and I remember what it was but it won't work when I put it in. Now after many failed attempts to unlock my phone its disabled for an hour. And I don't want it to get disabled for an even longer period of time if I fail to unlock it again.
How can I disable and unlock my phone (step by step or video tutorial link would be nice), without resetting the phone and loosing all my photo's and contacts and stuff, also without connecting it to the computer?
Please Help.
**Best Answer awarded to most helpful answer**

IPhone won't connect to laptop?

My iPhone 5c seems to not be able to connect to my Dell Inspiron 15 Windows 8 laptop. The problems arose very unexpectedly and nothing was wrong before. I changed my iPhone cable 1 or 2 months ago and my phone and laptop would still connect so I know that that is not a factor playing into these issues. I restarted my computer several times, but there seemed to be no luck there. I have updated to the newest version of both my iTunes application on my computer, and I have updated to the newest version of my Windows, but nothing seemed to change. I've also tried plugging in my iPhone cable into several different USB ports on my computer, and yet still nothing has changed. I'm running out of room on my phone, so I need this issue fixed quickly. The reason why I'm trying to fix this issues is so that I can import photos from my phone onto my computer to create more room. So, now I have been stuck in this dilemma for about a week or so now, and I need the problem fixed quickly so if anyone has any ideas please, let me know.

Using someone else s old iPhone?

I currently have an iPhone 5. My sister has a 6 currently but she had a 5s that isn't used and while I'm due for an upgrade IIm holding off for another month and a half until the next iPhone comes out. Is it possible to just put my SIM card in her old phone and use that or is it more complicated? Like do I have to go to the apple or Verizon store (my cell carrier) to do this or can I just do this on my own?

How to tell if my iPhone is unlocked?

I'm trying to unlock my iPhone from T-Mobile to give to my friend who has Verizon. But we had to unlock it first. It wouldn't even start up so I put my original T-Mobile SIM card into it. Well we got the email today to explain how to unlock it. All it said was put in a SIM card and follow the instructions. It did set up with a different service provider but I don't know if it is unlocked. It's an old SIM card and doesn't have service anymore so I can't call with it.

Is the IPhone 5 still a good buy in 2015?

I'm getting my iPhone 5 tomorrow, and I wanted to know that if it's still a good Apple device worth a buy this year and I also want to know if it has any any battery problems?

When taking a photo on an iphone do I need to keep finger on button for flash to work?

When taking a photo on an iphone do I need to keep finger on button for flash to work? - 1

Added (1). People asked me to take their pic but the flash did not work they blamed me for taking it wrong. I pressed the button until a square came up and I let go. Should I have pressed down for a few seconds?

Added (2). I think the flash WAS turned on but I did not press long enough?

My Wi-Fi says that it's connected but it won't load?

I have an iPhone 5s and it says that it is connected to my Wi-Fi, but whenever I try to use Instagram it says that IIm not connected to the Internet and whenever I try to search something on the Internet it says it's not connected even though it says it is.