Hi,
You need to hard reset your phone.
'''Be aware that a hard reset will erase all your downloaded apps and user data. It will restore your phone to a factory default condition. It will be like when you first bought it.'''
''Before you perform a hard reset:''
Back up your phone using the backup feature in the phone, so that you have saved your important information.
Fully charge the battery
Do not have the charger connected when you perform a hard reset.
Here is a link that shows how to perform a hard reset.
http://www.hardreset.info/devices/blu/blu-studio-60-hd-d650a/
Be patient, a hard reset takes a few minutes.
Try your phone first before you restore it from the backup you performed earlier to make sure that it is working correctly. If you restore it and it begins to malfunction it may be an app or corrupted setting (which has been reinstalled from the backup) that is causing the problem.