The customer service in McBub have given me a file to upgrade the firmware on my tablet. The file is a .rar file and my tablet doesn't recognize it. Any idea what I can do with it? I paid over 200 dollars for this tablet from McBub about 6 months ago and the battery never worked. I am now left with nothing and McBub are giving me instructions that don't work. They sent me a 9-page long word document with half the instructions in chinese, I am stuck at the first step of 30 . They refuse to take the device back to repair it. I suppose I have just wasted my money, haven't I? Do I have any come-back at all? Thanks in advance. At least I have now learnt never to buy anything expensive from on-line retailers.