It's a legit question, although the tone of it kind of gives an air of entitlement rather than philosophical inquiry. I guess first question is, why would you expect not to pay? What's the alternative? The historical examples haven't born much fruit yet (e.g. Marxism and the like). Come to think of it, even in non-capitalist systems, you're still expected to pay your way. Only difference being that you're also expected to pay the way of others as well. Any more palatable?

flagamuffin already mentioned social contract somewhat in passing. That gets to the heart of it, at least on a political note. There are a couple 101 texts you could read that gnaw at the wherefore of the social contract. First one: Locke's Second Treatise on Civil Government. That digs around a little bit, esp at the beginning, at the question of why we pay for stuff and why we agree to provide services and accept services and generally help each other out. It's a fair amount of artifice for the sake of later points, but given that it helped inform the formation of our current society, it's got good social propaganda value and should be read just for that.

Then you should consider the prospect of life without social contract. For that, Hobbes' Leviathan. Chock full of mad quotable blurbs. Paints a pretty dire picture of life in the absence of social contract.

Then you could consider alternatives- already mentioned Marx, but also check out Plato's Republic, in which Socrates attempts to lay out the social/political foundations of an imaginary "perfect" society, mainly in order to illustrate its impossibility, and reason to default to a more imperfect political agreement.

I'm sure people could pipe in re. the economics of paying for stuff, but I never got past 101 on that so I'm unqualified to write about it. Scarcity? There are a lot of econ buffs around here from all sides of the political spectrum, wouldn't mind hearing their take.