When in doubt, check with your scheduler. Contradictions between different sets of instructions are (unfortunately) not that unusual. It could be a mistake, or that something was updated, but not across the board. It's impossible to know what's correct without communicating, unless there's a date provided on the materials.
IF you find that the correct scenario is the one you can't do, there's a possibility that they might be able to adjust it, especially if it's in a hard-to-fill location. In any event, I'd definitely investigate further, before deciding to cancel outright.