I accidentally ordered Forza Horizon 2 TWICE due to some issue I was experiencing... Gutted, I am using Borderlinx to buy from American store (In UK).
The only proof I had was in my Microsoft Commerce billing section under US Personal Account...
First guy was useless. He didn't have a clue.
Next person (A woman - not that it matters just as I said guy above), found all the stuff instantly and transferred me to Xbox team, who then after telling them what I had told Raquel refunded the extra game I had bought!
Customer service was amazing, and more importantly, Forza H2 is downloading ready for me tonight to play... and I can't Wait!
Bit off topic but I was so impressed, felt bad about buying it twice and it disheartened me but after that I'm excited as hell again!