My samsung galaxy note 10.1 won't charge, help?

I have Samsung galaxy note 10.1 WiFi (white). It was fine until now, but I started having problems charging it. I have it around for 3 months. Recently it wouldn't charge properly but I still manged to do something with it. I would turn it off then on and it would charge. But today I can't charge it no matter what I try to do. It shows that device is charging, but battery actually gets lower. I don't think that there's problem with charger but sometimes it shows red x on battery sign. When i append it again sign disappears. I don't know what to do. To add it all I had it sent to me from another country by my relative. So could anyone give me some advice? Thanks!