I agree with John and Dave, let Mac's know that they need to make an exception to their one year rule - it was their fault up front. Be sure and send them this link and our correspondence.
I always thought that the thickness of the spring is what's important. If they are the same thickness then cutting them might work or at least be worth a try if Mac's won't make things right.
I had my front end bushings all replaced a few weeks ago. I decided to keep the old springs because I have dropped about 110 pounds off my engine with the aluminum intake and heads. My local shop guy said he still had a heck of a time putting them in because they wouldn't compress with the weight of the car. He had to tie the car down some how. Sounded kind of weird to me, but hey.