If the pictures are saved in a secure folder, you can retrieve or view them by accessing a secure folder. Open Secure folder app >> input the pin >> Open Gallery >> Select the image you wish to unhide >> More (3 dotted icon) >> Move out of Secure Folder. You will be able to see the images in Gallery now.
1. Access your mail application, then tap the Menu or More Settings option.
2. On the Settings panel, tap the Account settings.
3. Tap Incoming Settings.
4. Find and update the Delete Email from Server setting.
Your mail now leaves a copy of the message on the server.
As your unable to make calls from the phone, to isolate the issue is with phone or sim we suggest you to please try with different sim card.