My iPhone will not Factory Reset using Itunes or Finder.

I have recently needed to swap iPhones so I had to factory reset it to get the rest of the person's data off it. Then, the Apple logo was flashing on and off. That's when I force restarted it using the buttons. Then the screen displayed an iPhone cable connected to a computer. Then, I did exactly that on my Mac, and then the finder window opened with my iPhone in locations. Then I restarted and updated the iPhone. After the Mac was done it came up with an error code (4013). I then decided to try it on another Mac and it had the same problem with the error code (4013). Then I tried with my Windows PC in iTunes and when it was finished the cycle it came up with the error code (2003). I then tried to use Tenorshare Reboot but that did not work because I was not willing to pay any money.

Please get back to me with an answer/solution ASAP.