Current DUET Brides: I want to change the contract...

I originally signed the contract for photo/video coverage for up to 12 hours on my wedding day (from noon to midnight).

Since my ceremony starts at 3:00 pm, I want to change the contract so that they will cover up to 10 hours (from 2:00 pm to midnight). It doesn't make sense for them to be at my house 3 hours before the ceremony.

I want to pay for my engagment session with the money I save by reducing the number of hours that day. But so far, they don't want to do it.

What do you think?