I brought the pink now tv box yesterday and keep trying to download the software but keeps coming up with error code 006 a problem with validation! I've read on here what solved people's problems and tried taking all bars off my internet and still the same also used my own hotspot on my mobile and it's still saying it! What else could it be?
A bit of a long shot have you tried to factory reset your router and maybe disconnect the power to the router for about 30 mins.
This might not be practical in your case, but have you any friends or family living close to you, where you could temporary take the nowtv box to see if the box finishes the download process on their home network, then take the box back to your house to see if it then works ?