UseLuna.com isn't one of those popular services that everybody's heard of, plus, "luna", meaning "moon", is what many would pick for an overnight delivery service. Don't rush the accusations without putting some thought into it!
I just did - UseLuna.com doesn't show up. If you google from UK, I'm sure you won't see it even with the right terms. All this hostility from the US company is totally unnecessary! Why not try to handle this in a friendly manner first, and then, if it didn't work, go nuclear? Litigation is the worst side of the US and trips over any desire to innovate and start any business here! This country has the highest number of lawyers per capita, and their high costs are embedded in every pricing model - it's crazy!