Provia 400H is E-6, not C-41 (are you cross-processing it?). My initial thought is if you still have the cartridge, pop it open and tape the film back to the spool (or the little bit that is still attached to it), put it back in the cartridge, and take it to a pro lab and tell them what happened so they know there's an extra little bit of tape in the cartridge and can handle it appropriately so it won't gum up the works.