How do I fix my phone 4G metro PCS Samsung model SCH-R900 that appears to have faulty touchscreen. For example if I press #1, it shows number 3 on the screen and when I press number 3 and 4, it gives me different numbers. What can I do to fix the faulty touchscreen of my Samsung SCH-R900? I would really appreciate your useful assistance regarding this. I hope to hear soon from you guys out there. Thanks.