At the time, I was thinking "Well, no shit. I already knew that..." and then found a work around on my own.
A couple times my responses somehow earned me a reprimand by MySupport itself, to the general effect that,
I would appreciate a friendlier reply since we are part of a team. I would have been friendly if you had given me the answer you finally did after I re-explained everything I had already explained 80 different ways, that you could have answered based on the information from the initial question.
Another time, which took over 2 months to resolve, I was looking to order a common kind of hardware that attached to the shelf a different way than was listed in the catalog. I found one in the catalog that was similar, but had the wrong connector. I stated the wrong number, and showed side-by-side views of why it was wrong, next to the good kind which we already had some of but wanted more. I asked a simple yes/no question: if it was possible to order the other kind. If I can't order it, I can't order it. Simple question.
I think I literally had around 20 back-and-forth replies, and at least 3 of them told me that I should order the part number I had already said wasn't the right one. Pictures, diagrams, rephrasing, reasons why the laws of physics required the different connector. I took photos of it in detail, even showing it next to a measuring tape to prove it was a certain length, and zoomed out to show the full size, circles, arrows, and even color-coordinated comments with different colored arrows to indicate thoroughly that the one in the catalog was not the right kind, but they just couldn't grasp it and would never give me no for an answer. At one point they tried to tell me that I wasn't even looking for what I was looking for. I finally asked for them to let me contact the actual manufacturer of the company that makes the old style, which they did tell me, and I asked that rep and he replied exactly what I needed to know in about 2 sentences of explanation: they don't make it like that anymore. Done. The rep even sent me a schematic of the exact piece I was talking about, and told me he would bring it up at the next meeting that they should reconsider the old design.