I had the same problem and the only solution was via SDCARD. You have to download a right firmware for your tablet and put in a SDCard like this:
Here is instructions in this tablet without volume keys and Home key. Everyone asks how to do the recovery:
upgradeable via the SD-card:
1. Unzip the contents of the archive to the root of the SD-card;
2. Insert the card into the tablet and switch it off;
3. Press the power button + reset at the same time.
4. Release the power button and after 2 seconds the reset button.
If you did everything correctly, wait a little and you will see the display of the update process.
In the case of successful update a caption that the card will be learned. After that, remove the card and restart the tablet (after reset).
After the software update be sure to do a factory reset via the menu android.
If after the update does not work for touch screen -. In your hands is a tablet other revisions