My friend got a new phone from 3, an ericsson mobile, 2 months after its not working. She went back to 3 to get it fixed, they sent it to get repaired. After 2 weeks she got it back with a note saying sorry the warranty is not valid, cos its a water damage. She knows she didnt get the phone wet and there is no trace of water in the phone so they said it may have been some moist in the phone earlier. And they refuse to help her. What can she do?