I did see what I could find. Can you please try these steps and let me know if this helped.
Take the battery out of the phone for about 10 seconds.
Then with the battery out plug in the phone.
Wait a few seconds.
Put the battery in and immediately press power.
Denver Social Care Team
I've had the same issue with my S ii recently. I'm trying to get it to charge and even after taking the battery out it is not holding. I'll have to take it in to get looked at. It's only six months old.
I'm sorry to hear that. I would recommend taking your device to your nearest Service and Repair location where they can determine the root cause of your issue. Click on the hyperlinked name to find your nearest repair center and to create an appointment for your convenience.
Sprint Technical Support
Community Hours: 9am-2pm CST Sunday-Wednesday