Tell them:
“Birth control is not a right. Anyone choosing to use birth control should spend their own money on it.”
or,
“I should not be taxed to pay for someone else’s birth control.”
Keep it simple. This should not be on your dime. It is wrong to force you to pay for it.
Disastrously wrong answer. Tell them there is no argument about contraception out there, only about the government attacking religious freedom. Explain that they have trusted sources of information who are lying to them, that no one has proposed restricting their right to buy and use birth control and no one ever will.
Tell them they should direct their anger at those who are lying to them and needlessly alarming them for political gain.