There is no contract. Calling it a "social contract" is basically just admitting there is no contract, since you have to make this up.
We are born, and then bam, we are forced to pay taxes just because we are born. And if we don't, the government uses violence against us. We have no choice not to use those public services, because they often times have a monopoly on them.
I can't go out and build my own roads. I can't withhold my taxes and give the money to whatever school I want my kid to go to. They force the money out of our pockets, and spend it on stuff we need, because apparently humans aren't capable of spending money on things they need.
And even if we did use those public services, it's still theft. If I took $150 dollars out of bank account, paid myself $75, and then spent the other $75 on groceries for you and put them in your fridge, would you say that's not theft if you eat those groceries?
Interesting how all of this revolves around currency that is produced and regulated by the government ---