Is it under warranty? Put in a repair ticket. How new is it, is it in the return period? Did anyone drop it or damage it? If it's a software issue, a factory reset should solve the problem. You don't say anything actually about what's broken/not working, how is anyone supposed to help you troubleshoot? You have to be specific -- not just say my phone is broken.
@waffle5342 You don't mention which exact phone you have. The A series have limited memory so installing too many apps (or anything else) can cause the device to be slow, sluggish, or act erratically.
@waffle5342 Samsung makes many different models with varying storage and computational ability. When you bought it on eBay did it not mention the model of the phone?
