Most of the responders here are just obvious trolls. It's easy to sit at your keyboard and harass people who are asking honest questions and hoping for honest answers. One word can describe them: snide. And like you said, they'd be begging for help and understanding if the same thing happened to them. This is not your fault - it's Apple's. With hundreds of millions of iPhones sold, there's just no way that everybody with an iPhone will be within even a hundred miles of an Apple store or authorized repair service. Plus Apple has gone way overboard in its security systems, in my opinion - which is how I got locked out of my computer (El Capitan) for the first time in all the years I've had Macs, starting with the G3. As if all of us work for the NSA, FBI, some police department, or, say, Target or Chase - all of which (and many many more) have been hacked anyway. It won't be long before we read of hackers who have broken the iPhone's security system.
Like a couple of others have advised, I wouldn't upgrade until you know what the repair did to your phone. Even then it could be risky, since Apple is the biggest control freak of a tech corporation ever (like, you don't own the music you buy on iTunes, you're licensed to play it). If you don't absolutely need to upgrade, don't - don't upgrade just for the sake of upgrading. You could easily get by until the iPhone 7 comes out, if you're someone who buys the newest version every time. Bottom line - don't upgrade unless it's vital; instead wait for the new phone, probably late this year or sometime in 2017.