While I don't completely agree with the way the OP did not go to Hennessey, I also empathize with his situation.
Customer service is important and you have to do your best to help a customer when an issue arises. I am personally a 'vendor' in another industry, sell products strictly online, and deal with warranties on a regular basis. When one of my customers has an issue with their product, regardless of the brand, they know or have been told to come to me so that I can assist them with their warranty in any way possible. That doesn't mean, "come to me and I'll give you the manufacturer's phone number or email." It means taking an interest in their issue, contacting my rep or their warranty department on the customer's behalf and using my company's leverage when necessary to assist the customer in getting a satisfactory solution that is fair to both the manufacturer and the customer. That's the least I can do to take care of the people who are purchasing things from my company instead of someone else's.
You build a reputation in any industry. You can be an average company that fulfills orders and sends the customer on their merry way, or you can take an interest in each and every customer and go above and beyond to make sure they come back to you and tell their friends to do the same.