My first nic order for DIY was from NudeNic. It was a small bottle of 100mg nic. It took them almost three weeks to get my order fulfilled. I'd read the term "peppery" back then quite often but never knew what it was. I found out my very first mix. Strait pepper, NN lost me as a customer that day. When I dumped it, it was yellow.
I got my next stuff from Vaperstek. I've been happy ever since.
This does not sound at all like NN as their QC is superb. Having some professional experience in purchasing and for four years as a consumer with this vendor and other majors in this industry I've but once encountered what you describe (with another source). It too was a sample. Had you gone back, I'm certain NN would have worked closely with you to ensure you the opportunity for a proper sampling of their product. At least that's what I'd have insisted on.
Good luck and Happy New Year.