Error 4013 on iPhone 4S after 7.2 update

Hi guys just to let you know we had a problem updating the iPhone 7.2 on the 4s

It crashed during the upgrade showing errors 403, 405 & 4013, did everything apple told us to do ie re install and still no result ! Looked at the forum and seen that other apple users have had similar problems. With not being very up on tech stuff decided to go to the local apple store for help. After putting the phone on one of the Apple Macs and doing the phone was saying the same fault 4013. Apple staff were not helpful and kept saying as the phone was 16 months old and out of warranty that we would have to pay £140 to send the phone off to find out if it was a phone fault or a software problem, we explained over and over again that the phone was working perfectly well until the update so it was apples fault not the net work providers ! told us to go to the retailer we bought the phone off as it's a consumer issue not apples ! So we went to our local O2 net work provider and explained what had happened, with O2 explaining apple we're in the wrong (which we knew) went back into apple asked to speak the the manager who was the same person as before, had a heated discussion. I asked to speak to someone above him so along came a different manager with the same reply to blame it on the net work provider!! I responded by getting a manger from the O2 to come to the store and battle it out regarding who's fault it was !! 10 minutes later after persuading apple to put the phone on a diagnostic machine the genus member of staff looked at the manager and took the phone out of it's protection case and said they would replace the phone FREE OF CHARGE admitting the FAULT was caused by the 7.2 software update !!! This took 3 hours in the store to get sorted out ! If anyone reads this please stick it out and get the phone replaced free of charge and to apple sort out the update !