iphone 5s recovery mode

Recently tried updating my iphone 5s with the latest update which i believe is IOS 8.3 however this failed to complete and is now stuck in recovery mode. Apple have been of no use maybe because my phone is out of warranty and they just don't seem to want to deal with devices out of warranty.

Apple are telling me it might be a hardware issue even though my phone was working perfectly fine before I attempted the update. Obviously they will say that because now my phone is out of warranty I will be charged for any hardware updates.

Anyway, I have tried all possible suggestions like updating the operating system on my macbook pro and itunes to the latest version, i have tried connecting by holding the different combination of buttons and also tried rebooting it on different computers with the latest itunes on. The phone has been stuck in recovery for 4 days now and still no closer to resolving this.

Any suggestions will be appreciated greatly.