you've got another think coming

You've got another think coming AND You've got another guess coming (= You"ll have to rethink your position. The second part of an expression something like, "If you think so-and-so, then you've got another think coming." ) — ты очень ошибаешься; ты глубоко заблуждаешься

Example 1: If you think I'm going to pick up after you, you have another think coming. — Если ты думаешь, что я буду за тобой убирать, ты сильно ошибаешься.

Example 2: If she thinks I'm going to support her, she's got another think coming.

Example 2: You don't think you're going to get away from me, do you? Well, you've got another think coming...

Example 3: He's not my boy, you are, and I don't care what you say about him! You got another think coming if you expect me to put up with you disobeying me! And don't even think of stepping one foot outside this house tonight or any other night until I say so. Take yourself to your room this very minute or else I'm not gonna be responsible for what might happen if you stay in my sight. (Amina Gautier, Yearn)

The common misuse of this expression goes thus: "If you think this, that, or the other, then you've got another thing coming."