If communication is poor, and they have fallen short on their obligations, then the most powerful message you can send to the company is threatening to dispute the card, then follow through disputing the transaction due to not providing product as described in a time frame described. If the situation is worse, then just do what you gotta do to get your money back, and send a clear message that your experience was unacceptable.
To any of you in this thread I've done business with while at Elite, I hope my honesty and clarity of your own situations, despite some times being the bearer of bad news was a satisfactory experience. If you had a bad experience with me personally, then I really am sorry. Send me a PM, and if there's anything I can do to make it up to you, I will. I agree with most of you in that telling it like it is, even if it's bad news, ends up being the best solution.
The bottom line with fancy performance parts companies is that unless it's on the shelf, most high end companies need a fair amount of time to produce the parts. That's no excuse, but it's reality. As long as expectations are realistic and reasonable then I see all parties winning. This industry is ripe with opportunity for anyone who can communicate effectively, and provide quality products in a timely manner at a fair price. I suspect those that are operating ethically are seeing a lot of success. I suspect that there are also a fair amount of non-ethical shops doing just fine too because of supply and demand. It's easy to get away with crap when you're the only one providing a service or product as in the case of the op. I have no idea who your problem vendor is, nor do care to know at this point. In a perfect world, this mystery shop will step up their game before it comes to a call-out. If they continue to excuse themselves and ignore you, I hope you do us all a favor by taking the time to report them to the BBB, and give an honest review of your experience with them, so we can have that available when deciding where to buy our parts.