My tablet seems to have have got stuck when trying to reset it to factory settings after it got stuck in the boot loop. It keeps telling me "error, data wipe failed", then flashes something with regards to s.d card. Sometimes it comes up with the menu but won't let me click on anything?
Try to enter Recovery Mode and factory reset again from there.
To enter recovery mode, power off your phone and press and hold the power button along with the volume down button. The Recovery Mode menu should appear and there should be an option to do a factory reset.
See here for more info on how to enter Recovery Mode.