I’ve never ridden in a Voltaire, so I can’t speak to their quality or their customer service, but…
Sounds like the saddle you got didn’t fit your horse. This happens, and it can happen with any brand for a variety of reasons. As others have suggested, your first call should have been to the rep so they could have had the opportunity to help you solve the problem. As a professional, you should know enough about how to fit tack (including saddles) to identify if there is a serious fit issue. Riding in a saddle to the point of rubbing your horses’ back raw is inexcusable, and that is 100% your fault. Signing a sponsorship with a brand that you had no prior experience with (and promoting that brand to your clients) seems foolish to me, but I’m sure you aren’t the first or last person to do this. Totally understandable that you now feel guilty about one of your clients buying a saddle based on your recommendation of a brand you didn’t have any experience with…
Saddle companies offer trainer incentives because they want their saddles to have visibility and they want happy professionals who will act as brand ambassadors. If after signing the contract, you went through the process of working with the company to remedy any issues, and ultimately decided you did not want to keep the saddle, my guess is that they would have allowed you to return it, and would have let you out of the agreement. Instead, you broke your contractual agreement with them by selling the saddle to someone else and then decided to trash the brand on a public forum? Again, I don’t have any personal experience with the Voltaire brand, but given the short period of time you had your saddle, and the fact that several people here have said their Voltaire saddles have held up well, I wonder if you either just got unlucky with some faulty stitching or a poor hide, or that you aren’t caring for the saddle properly.
Personally, I ride in a CWD, and love it (and I also know plenty of people who don’t love their CWDs). When I ordered it, the rep suggested that I might prefer grain leather or buffalo rather than calf because of potential wear (I was riding 5-7 horses a day at that point). I went with calf anyways, always take great care of it, and several years on it’s still in great shape and is holding up nicely. At my barn we had a few Childeric saddles for lesson horses. They aren’t my personal favourite to ride in, but they do the job well enough. Do they look brand new? Nope, not at all. Between extensive use and the dubious cleaning methods employed by children those saddles have had hard lives, but several years on they are still functional and doing the job in reasonable style. I’ve seen Butet’s from the 90’s that are still trucking (some in better shape than others) and I’ve also seen 1-2 year old Butet’s/Childeric’s/CWDs etc in horrible condition… good care plays a big role too, not just the amount of use!
As far as I’m concerned, when I’m looking to buy a saddle for myself or for a client, it’s about how it fits to horse and the position it puts the rider in. From past experiences, I don’t think that saddle reps are always very good or very reliable at fitting saddles, and ordering a brand new custom saddle has always been a bit of a gamble re: fit. I’ve been pretty lucky in the past, but in general I’d prefer to buy gently used rather than new so I can try it on the horse and ride in it.
As an aside: As a junior, I rode with a BNT whose barn was at one point sponsored by CWD. Plenty of clients bought CWDs and plenty rode in other brands. It was common knowledge that the trainer was getting saddles and tack credits based on the fact that clients were buying saddles. As far as I know, nobody had a problem with that, and I can tell you that just about every saddle brand under the sun was represented somewhere in that tack room.