No, you can’t refuse to talk to them without imperiling your finances even further. But, you can ask for the details of your loan and verify that they are correct. Here’s a list of your rights under the Fair Debt Collection Practices Act (FDCPA).
And yes, they can take money from your paycheck. But they can do this only after they get a court order. You will get a notice from the court. Don’t ignore it. It’s essential to obtain a lawyer or get help.