Contact your cellular service provider and ask for Tech Support. Tell them what problem you have. Ask if they will walk you through the directions to perform a 'Hard Re-Set' on your phone. (This is something that needs to be done while they can talk to you.)
If this doesn't work, ask them for assistance in getting you a new phone. They'll be glad to help.
Answers & Comments
Contact your cellular service provider and ask for Tech Support. Tell them what problem you have. Ask if they will walk you through the directions to perform a 'Hard Re-Set' on your phone. (This is something that needs to be done while they can talk to you.)
If this doesn't work, ask them for assistance in getting you a new phone. They'll be glad to help.