Don't panic. These tablets are very hard to brick. You just need to reflash the correct firrware in the correct way

It sounds to me like the tablet is not properly off when you are trying to reflash.

You need to prepare your computer with the correct image to flash in phoenix suite.

If you hold the power button in for about ten secs, the tablet should power down properly. You may see a screen flicker as it goes off. This is easier to see in a dark room. Firstly charge up the tablet for a few hours to make sure that there is sufficient charge.

Then...

Get your image ready to flash using Phoenix suite and (if you have not done so already) hold in the power button for at least ten seconds to make sure the tablet is fully powered off. Then immediately connect the USB cable to the computer and Phoenix suite should detect the tablet and ask if you want to flash the firmware.

Choose 'yes' to Mandatory format and it should take baout 3 minutes to reflash the firmware. Once flashed it should reboot (you may have to press the power button) and then you will be back to scratch.

For general procedure, follow the video and instructions here

http://www.arctablet.com/blog/featured/phoenixsuit-flashing-tutorial-onda-v972-v812-allwinner-a31-tablets/

(I am presuming that it works in the same way for A31s tablets but I don't know for sure)

but choose the correct firmware to flash - latest Onda download here

for V975s version 5 tablet http://pan.baidu.com/s/1gdrGa9X

for V975s version 1 tablet http://pan.baidu.com/s/1o6I2G7w

Some other V975s android versions are available to download here

http://pan.baidu.com/share/home?uk=389436537#category/type=0 (first of 5 pages of firmwares)

best of luck

Pingu