Wow, that is the first time in about 40 years I have heard of them not saying, "sure, we can fix that." !! Well, your situation must be even more rare than I thought it would be after you said you had found reference to it in the manual.
Do pass on what you find.
I don't know where you are located but you might check around for other places that do serious brake work, maybe someone else in the business is aware of these and how to deal with them.
