Hello and welcome to planDisney, Kellie!
Great question! You are correct; you can call (407)939-1234 and speak with a cast member who will be able to reserve a room-only reservation. I love having that option, especially when I want to ensure I can adequately budget for my vacations, and having a room-only reservation makes it real if that makes sense.
With that being said, what you have described is interesting, and I am unsure why the week before and after your proposed vacation dates are available and not the specific week. I recommend calling back to check availability because perhaps your desired
Walt Disney World Resort vacation dates will be available at some point so that you can make your reservation. I hope this helps.
Please let us know if you have additional questions during this planning phase; we are here to help.
Have a magical time!
Raquel