Neos like neutral, and caridinas most definitely will not like a higher ph. If u want i can come over to help remove it - I have a bit of experience with that. I drained the tank - turned the filter and heater off before, of course - and scooped it out with my hands, and at the end I used a scoop, like from a brush-and-shovel sort of thing. U would want to keep your filter and media in a bucket with aquarium water.
And as jayc mentioned previously, you have clear grounds for returning the gravel. Get something that is clearly packaged, that you can look up when ur there.