Galaxy Samsang A3-freeze ,wont turn off, touch screen doesn't respond

My Samsung Galaxy A3 6 froze. It is on, The touch screen doesnt work, cannot swipe to open the applications. When i hold in the power and volume button it look as if it shuts down but then show the vodacom icon for few seconds and disapears, then the Samsung logo appears and flash a few seconds and then it freeze again.