After a very cursory review of the two sites, I could not see any similarity between them, pyledw, other than the fact that they both work to connect consumers with businesses. This is not exactly a novel idea, and ideas cannot be copyrighted anyway.
I also did not see any copyrighted content from one site that looked to infringe on the other.
And then, with the trademarked business names and logos, there was little similarity between the two. Trademark law centers on consumer confusion and I do not see that a consumer would confuse your business with the other business.
However, if you are worried by the threats of legal action (and threats to sue are naturally worrisome), I suggest you head to an attorney's office in your area and ask for a review of all facts. The attorney could potentially respond to the threats you've received with a "knock it off" letter sent to the owners of the other site. Hopefully this will work to stop the harassment.