Digital Refunds

So I bought GTA IV through xbox store because it was on sale just a few days ago and since I cannot buy The Lost and Damned or The Ballad of Gay Tony by themselves, I thought they might come with it. Little did I know, those DLCs can only be bought once you're in the game through the XBOX 360 marketplace. I tried to get a refund within 10-15 minutes of playing the game and it was immediately denied. I was wondering if someone can explain to me what happened here? I have only had the game for about 4 days now and played it for about 15 minutes. I tried contacting support and they told me to reply back to the email, which i did numerous times, and it was the same guy who denied it over and over. I got on the phone with support and through text but every time they told me the same thing, to reply back to the email. When I did it for the third time I think or maybe fourth, this time the guy did not even write back he just sent an email about closing the case. Is this what Xbox customer service has turned to? I'm not asking for an exuberant amount, it's only $7, I have spent way way wayyy more than that digitally but they cannot refund me that amount and take the game off the list? The only reason I want the refund is so I can spent more toward the "GTA IV Complete Edition", rumored to be on the horizon and should be coming out sometime this year, fingers crossed, and I will be buying it on Xbox. All of my cousins are asking me to switch over to Playstation already but so far i'm sticking my Microsoft... Why? If this is what the service has turned to then.. Well?

:)