Johnny, I think you should complain some more about it. You've definitely got the worst luck when getting rebates of everyone I've seen here. I bet it was even intentional they picked you! Exactly how many years ago did this occur?
I generally consider a rebate a bonus if I get it, because I don't buy things that I wouldn't otherwise use just because of a rebate.
I'm also pretty sure that not getting the rebate doesn't actually affect the product, other than a negative confirmation bias that the oil now "Suxxs" because they screwed someone out of a rebate. Are you 65 going on 8?