I had a same problem with my GF's phone and we did a hardreset on the device and all the issues got resolved. Try to reset your device by following steps:-
1.Power off the phone.
2.Press and hold Vol+ key and Power key simultaneously for about 10 seconds until the some option appear on the screen which are reboot system now; apply update from sdcard; wipe data/factory reset; wipe cache partition.
3.Use Vol+ key and Vol- key to move the cursor to "wipe cache partition" and press camera key to confirm it.
4.After 5 seconds, the cursor will be on "reboot system now" again and press camera key to confirm it. The phone will reboot automatically.
But make sure that you take the backup of all your personal information on the SD card and remove it.