where my photos taken in January by my Tablet went?

[AC Question]

Last Friday ( April 21, 2017) I went to Virgin Mobile kiosk with my Samsung Galaxy Grand Prime smartphone.

I had a water damage issue. The phone won't charge so I can't open it and recover my photos.

I had my Samsung Tablet with me and I asked the sales person what is the SIM card for which wasn't installed at the time I bought Tablet on December 20, 2016.The Tablet was set up without SIM car. In January I went on a trip in Himalayas for which I was saving almost two years. I took close to 700 pictures which were very precious to me.
When salesperson put SIM card into my Tablet the device restarted to do set up. He asked me for Google email address the Tablet was originally set up but I didn't remember. He tried a couple emails but it said to use Google account originally on device.
When I returned home I found the Google gmail address and Password I gave the salesperson in December when I bought my Tablet. After several attempts I was able finally to open the Tablet BUT .... ALL MY PHOTOS ARE GONE!!!!!
What should I do to recover them??? They are so precious to me. I bought the Tablet ONLY for the purpose of taking pictures, nothing else.
Please help!!!!!!!