The Deal with the Devil

She's abused at home and bullied at her school.
So what happens when she makes a deal with the devil?
Her life turns around and she's gone for two years, turned into a different person.
When she comes back everyone is shocked, her parents now scared of her instead of the other way around, the kids at her school are ask trying to apologise but she is gonna treat them the way they treated her.
She expects her life to be perfect now but I guess she didn't understand the whole deal with the devil.
The devil greets her again when she starts to get settled again.
He tells her the deal again, but now she actually listens and understand, and the price is deadly.