Yeah, 5 months is a long time. I think you have to eat it.
And you missed the opportunity to 'launder' your purchase by buying a new one (as your replacement) and sending in the old one as faulty. Of course, by posting here you have completely eF-ed yourself. You could have gotten something in writing from MR that the SF work would 'fix' it, and if it didn't work (which it likely wouldn't), then you would have had a second chance at getting your money back or some other discount -- but I don't think that is going to happen now.
Sorry bud, but I look forward to the WIP about you reprofiling/grinding it.