Dead tablet. Wont charge. Wont reboot.

So, my samsung tablet has been playing up for a week or two. Not fully charging, a bit slow. Then this morning after an overnight charge it was at 23%. It was my intention to let the battery run to flat then do the power on / power off thingy, but it got down to 2% then completely froze. It's not charging, or turning on., just dead. I've tried all the holding power/ volume buttons stuff but still absolutely dead. Help!