my sony erricson K71 showing charging error stop charging what is the issue?

My mobile has stopped charging all of a sudden and giving message charging erroe stop charging. i tried using USB data cable to charge it but still its the same. can anyone suggest me what is the problem for the same? how can i fix it. the main concern is that i'v got my all contacts in it and i am not able to retrieve it. plz anyone can suggest me how do i fix it.