T - Mobile Would not honor refund Denver, Colorado

I was on a month to month cellular plan with T Mobile and had paid for a full month, $60, and canceled my account 6 days into that last month, July 2010, per my prerogative. When I asked for them to refund the pro-rated amount that I did not use they refused with no explanation. I have contacted their customer service office twice now and still have not received an explanation only that they will not refund the unused portion of my last bill. They say it doesnt work like that. Well how does it work T Mobile? I told you I would exercise my right as a consumer to make this report so that other consumers will be full informed and you said okay, go ahead.
Note:*The young guy in the store actually asked me: "what is pro-rating?"
Im not impressed with this company at all. I canceled my account to get service with better coverage with a better company.