I'm sorry that you had THAT bad experience with Apple Support, learn from it, I have the latest years.
Unfortunately that is how the trail is going.
You won't get any good support or understanding before you come to a Senior Advisor at Apple I've learned.
Just don't accept sit in hours with newbie support, demand more.
Things have been going downhill in many areas since Steve died is my experience. They have no genius that control Apple anymore and it shows in lack of security in softwares and in lack of security in the company, but a businessman who only know what he knows.
But it sure is good that more Apple Stores is coming up for us to seek support when problems seems to be more and more. 😉
I TOO have this bug with Game Center and more problem with 9.0 and even more other buggs in 9.0.1 & 9.0.2.
The worst upgrade EVER.
But it haven't gone that far that I considered seeking other systems, I'm too deep into Apple.
But I've learned that it isn't the same Apple today as some years back.
Got to accept it and demand more in our contact with Apple, they are what they are today.
A company that is in transition.
No tech-daddy that look out for us anymore, we have to do that ourselves now.
In future updates I'll wait until XX.1 before upgrading iOS
Fortunately my El Capitan upgrade went flawless, gotta be grateful for that 🙂