Dropping the van off...

Every Thursday morning, we clean my dad’s office building. The guys and Suzanna usually go in the green van and along the way they pick up a co-worker of my dad’s and they carpool over there…then Mama, the little boys and I go in the little van. This morning, my dad also had to drop off the big van at the shop on the way in…So, here’s how it goes…
Papa: Don’t forget, Daniel, we have to drop the van and pick up Phil.
Ben: Why did…um,…who dropped our van?