American Way Tree Service

We contracted with American Way Tree Service to take out our old oak tree, grind the stump, put in fill dirt, and reseed the area. American Way did a great job of taking down the tree and grinding the stump, but they still owe us the fill dirt and seed.
We had other projects going on in the same area of the yard and asked them to hold off on the dirt until we needed it. We have those projects done and have called American Way for the fill dirt. They have promised they would deliver the dirt, but have not come through. We have followed up many times and we either get an answer machine or someone answers and hangs up. We have left a message giving them the option of paying us back for the dirt and seed. We have not heard back from them.
UPDATE 1÷23÷16
I finally got a refund of $ 100 for the dirt that was never delivered. They paid $ 65 in cash and $ 35 by check (pending it clears).