Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
So we can help you, if possible. I need to know the full name brand and model of your cell phone, and also what company you pay for your phone service.
Allright, if you still know your google / gmail address and password.
Then you can use a computer and go to this link, sign in, and you can track, lock, or erase your phone
Once you sign in on that link using the google / gmail address the phone was registered to, you will be able to track the phones last location, lock it, or erase it.
If you are satisfied with the solutions / answer I have provided please remember to click and submit a 5 star rating, as that is the only way I am credited for assisting you.Thank you,Dustin S