denied payment of accrued paid days off

I recently left an employer for another healthcare facility. The hospital required a 30 day notice. I had discussed my plan to leave with another employee 2 days prior to intending to see the department manager. When I went in to give the notice on what would have been day #30, my manager had taken the day off, and there is no assistant manager available to talk to. My co-worker who was also working that day asked if I was successful in meeting with her- and I told her of her absence and that I left a dated note saying that I came in to see her and that I would be back he next day and it was important that I speak to her. The employer is now saying that I didn't work the required notice even though the manager admits that I was there to see her on day #30. Am I entitled to payment?

By law you are entitled to be paid your agreed upon rate/salary for all hours worked. Regardless if you did or didn't follow internal company policy regarding advance notice of the last day of work. OK?