When you connect the phone to your computer it should be seen as a physical drive. You should see two drives. One is the SD card and the other is the internal memory of the phone.
For this to work, make sure you have Z10 the drivers installed. By installing the Link sofware the drivers are automatically installed when the Z10 is connected.
As for SD cards, when data is erased, it is not like with DOS and some operating systems where only the header ID flag in the directory table is changed, and the data is intact until some other data writes over it. The deleted flag tells the OS that the space is available and the space can be overwritten with new data.
In Windows when a file is normally deleted it is flagged to be part of the Waste Bin folder which is designed as a system folder. The file is not really deleted while in the Waste Bin Folder. It is in a sense re-alocated. When you tell the waste bin utility to delete the file, then it overwrites it entirely with the equivalent of 0′s. This makes the file securely deleted.
With SD cards the system is different. There is no waste area for the files. There is no easy access to re-set the delete flag. If you did more writing to the card, the flagged data can be easily over written. There are some utility programs out there that claim to be able to undelete files on the SD card. You will need a Windows computer and a card reader to do this. I found some software that are supposed to be able to do this. I never used them, or know if they will charge a fee to use it once it claims it can undelete the file.
Recovery Toolbox for Flash is solution for you