So a wee update...
Thanks again to Astral for your advice. i debated what to do for a while but I really wanted this AIO and nobody else has it. If they hadnt sent an actual photo I probably would have avoided but I decided to take the risk. I replied and asked for a black version of the Nitrous instead of the silver and said I would take the AIO and asked if they could add in the black spare cartridge kit as compensation. They replied within a day saying they have the black Nitrous but no stock of the black AIO cartridge but would throw in 'some freebies'.
I told them to go ahead and asked how long delivery would be, they said 4-6 days and I immediately got a dispatch email with a tracking number that within 24hours tracked the package all the way here. Weirdly it arrived yesterday even though the tracking said it was still at the Royal Mail distro in Heathrow after leaving customs but the main the is it arrived.
Checked and they are both genuine products, AIO sealed (Nitrous tin doesn't come sealed). the 'freebie' was a pack of Bacon prime which is a bit poor but I'm just happy it all arrived. I will still not be using that company again but all ended up OK.
Thanks for everyone's 2 cents