I phone Larini, and they made it sound like this is not a normal thing, and that I should contact Sector111 for the warranty return, which I have done. Larini exhausts do have a lifetime warranty, which is pretty awesome.
I may not know the result of this for a few more days, but I'm tempted to pull this for sale thread because I may get a brand new one on warranty replacement. If I don't get a replacement, then Rob at Dietschwerks will take the muffler. The muffler is still fully functional, and it could be possible to get the loose change out of the muffler somehow.