I would take it up with vivitar or the amazon seller and make them pay for it,
happened to me on when I bought a hard drive power source.
First thing it did was fry my hard drive! Made them pay for a brand new one.
Such a shame that today's vivitar is not the good old vivitar from back in the day.
I bought them used from a seller off Amazon, so I doubt Vivitar would be willing to pay since it didn't come directly from them...I also think I would have a real hard time getting the seller to pay for something like this. But regardless, I will get it fixed.
As I said, I have never sent anything in to Canon before, but it sounds like they do cleanings and stuff as well when you send it in...is this true? I know my viewfinder could use a good cleaning.